35 Rem light loads and primers backed out

[CGT80]

Yesterday, I made it to the range to try out a Marlin 336 in 35 Remington, that I am getting setup for my neighbor. I full length sized the once fired brass. The Hollywood Universal 12 station turret press was setup so it almost cams over when sizing. I trimmed to 1.910" and deburred the case mouths. A Lyman M die was used to add a bit of flare. The primer flash holes just clear a 5/64" drill bit, which is 0.078". I read that some people use 0.080" holes for light loads, but I didn't find much data on how big to go.

The loads:
copper plated 38/357 bullets in 0.357" diameter, 158 grain hollow point
Seated to 2.121"
Red Dot 5.0 to 7.0 grains
10 rounds with CCI 350 large magnum pistol primers
60 rounds with Federal 210 large rifle primers
slight crimp with RCBS dies to take the flare out of the mouth

Chrono shows 800-1000 fps for these test loads.

The pistol primers seem OK. Six of the rifle primers backed out, and one primer blew out completely. The case necks had some black soot on them. I managed a 2-2.5" group at 25 yards from the bench with a sandbag under the front of the rifle. Sights are stock irons, and I am not a great bullseye shooter, and there was a bit of a cross wind. I think my 30-30 and 30-06 may be doing a bit better as I could drill an 8" plate over and over at 100 yards from the bench with peep sights. They also use NOE Saeco 315 rifle boolits that are sized to 0.311".

This rifle is going to be for plinking for my neighbor. He would probably be very happy to hit the 8" plate at 100 yards. Right now I am not looking to get a mold for this rifle, so I was trying to use the bullets I have. I also have lswc 158 sized to 0.357". I have a 158 RN mold that I could use as cast or get a sizing die bigger than 0.358" For now, I think the primer issue is the most important.

Do I need to enlarge the primer pockets?

Go hotter with the powder?

My load books show data for GC boolits and the charge is higher than what I used, and the velocity is higher than what these plated bullets are usually run at by other people.

The primers on the left column are large pistol mag and all others are large rifle.

http://i1112.photobucket.com/albums/k484/CGT80/Shooting%20Reloading%20and%20Boolit%20Casting/IMG_20140905_212504_707.jpg

All of the brass with backed out primers, has what looks like a crimp to the case mouth. The right one, of the three, did not have a backed out primer and the neck looks more normal. I can't tell if the shoulder is moved on the brass. Could the case mouth be that way from the brass being shoved into the chamber?
http://i1112.photobucket.com/albums/k484/CGT80/Shooting%20Reloading%20and%20Boolit%20Casting/IMG_20140905_212617_246.jpg

[RickinTN]

I'm thinking you have sized the cases too much and created an excess headspace situation. It's somewhat easy to do with the 35 cases. The primers are backing out to fill the space between the base of the case and the breech face. I've never seen it before but the shoulder was apparently pushed back so far that the neck (the distance from the new shoulder location to the mouth of the case) is longer than the neck portion of the chamber and when chambering the cartridge the neck is "pinched". If your sizing die is set to bump the shellholder this usually results in a too much headspace situation. Usually in 35 Remington the sizing die should be backed off of the shellholder about a 1/4 rotation to keep this from happening. I'm not sure how your cases could be salvaged other than trimming them an additional amount (how much?) and re-fire-forming to fit the chamber.
Good Luck,
Rick

[Tatume]

The firing pin strike can push the case forward in the chamber, especially when the cartridge has a very small shoulder, like the 35 Rem and 35 Whelen. When the powder ignites the primer backs out. It is normal for the case to expand and reseat the primer against the breech face. If the load is very light, this reseating does not occur.

Cases used for very light loads should be kept separated and used only for light loads.

[Nobade]

Don't fire light loads in a 35 rem. The primer has enough force to shove the case forward past the shoulder, the crimp you are seeing is the mouth of the case being shoved into the bore. Take a look at the distance from the head to the shoulder on a normal case and compare it to what you have - yours are going to be a lot shorter.

Be careful if you reload those cases. They need to be expanded to cylindrical and re-necked down, to establish the shoulder location. If you load them with normal loads and they do manage to fire, they'll likely break in half due to excess headspace.

-Nobade

[jrmartin1964]

Obvious signs of "something's not right here" (backed-out and blown primers, case mouth deformation), and yet firing continued?
I can agree with loading 10 cartridges with a particular powder/primer/projectile/etc. combination for testing (my preference is 5 per combination), but 60?
Especially when you're operating "outside the manuals".

The case that suffered the blown primer should be flattened with a hammer and discarded. I'd probably do the same to those with deformed mouths, too.

Jim

[MostlyLeverGuns]

Agree with RickinTN, you have a headspace issue, either created by sizing case too much or from firing cases with light loads. The tiny shoulder on the .35 Rem does not provide much support for firing pin impact. Full length size die adjustment is very critical with this cartridge. Some Marlins also have 'generous' headspace tolerance. Normally, full-length sizing for the .35 Rem can and should be avoided. You might try 'partial' sizing using the full-length sizer backed out so that the case shoulder is not moved. There are multiple discussions about concerning light lights creating 'headspace' (moving the case shoulder) issues on many different rimless cartridges on this and other forums. The .35 Rem is one of the usual suspects. Cases used for light loads should be kept separate and marked. Cases that you have already full-sized with the die touching the shellholder may need to be discarded. Enlarging primer pockets may avoid the primer backout issue, but it will hide the potential problems of 'artificially created' excess headspace.

[Scharfschuetze]

I think that the pressure in the primer pocket is greater than the pressure in the case with your light charge of powder and is pushing your case forward and pushing the shoulder back. Your issue is very common with rimless-bottle-neck cases when used at very low pressures and the 35 Remington with its abbreviated shoulder and thin brass is probably very susceptible to this "shrinking."

Enlarge your flash hole to reduce the pressure in the primer pocket to less than the pressure in the case and your problem will go away. I've done this for many cartridges (especially when the kids were learning to shoot) and it is an effective way to preclude your "shrinking headspace." I just finished prepping a batch of 120 Lake City 30/06 cases in this manner as even these stout cases are susceptible to "shrinking" with the very light loads that are under discussion.

Over the years, I have verified this shrinking phenomenon and its cure in different rimless calibres caused by ultra-light loads using measuring tools from Mo's, RCBS and Stony Point (now Hornady). It is a repeatable experiment and is probably what is behind your problem.

You may also enjoy less extreme spread and a smaller standard deviation for better ballistics with very light loads using an enlarged flash hole.

As noted above, mark such cases and keep them segregated.

The second option (as you surmise) would be to increase chamber pressure and get your velocity up to about 1,300 fps or so.

A third option would be to use a heavier bullet sized slightly larger than your current projectile to increase pressure and still keep your velocities low... if that is your goal. I have no idea what your actual bore size is, but a .357" bullet may be a tad on the small side as most 35 calibre rifles (modern anyway) use .358" jacketed bullets and I size my 35 Whelen boolits to .359" diameter. I understand that Marlin Micro-Groove bores can be slightly larger than conventional bores and here is where that .357" diameter bullet may be a bit small if your Marlin has the Micro-Grove rifling.

A couple of other notes:

There doesn't appear to be any powder residue on your case necks, so that's a good thing and indicates that you are at least obturating your cases in a radial sense.

Large pistol and large rifle primers are different heights with the LR primer being slightly taller. Given that, the LP primer will seat slightly deeper in the primer pocket than a LR primer. Probably not too important here, but I do note a missing primer in your LP loads. That's normally caused by excessive pressure and that's just the opposite of our discussion here. Any ideas? Loose primer pocket? Double charge?

[CGT80]

Obvious signs of "something's not right here" (backed-out and blown primers, case mouth deformation), and yet firing continued?
I can agree with loading 10 cartridges with a particular powder/primer/projectile/etc. combination for testing (my preference is 5 per combination), but 60?
Especially when you're operating "outside the manuals".

The case that suffered the blown primer should be flattened with a hammer and discarded. I'd probably do the same to those with deformed mouths, too.

Jim

That is exactly what I did..............10 cases per different powder charge for 4 different loads, actually 20 for my mid load of 6.0 of red dot, and 10 with large pistol primers to see if they were suitable for light loads in a rifle.

I knew that backed out primers were a possibility, and I am also not new to loading outside the manual. Most manuals don't list data for light rifle loads with pistol powder and plain base boolits, which is what I have worked on in the past. I needed to see if the loads varied, such as maybe the 7.0 grain load having sufficient pressure, but it looks like it does not.

I will keep this brass for light loads only. We have no reason to load hot loads for this rifle, so the lightest load that is actually reliable, is what we are looking for. I would rather start low and work up, and I know Red Dot is liked for the light loads. This is however my first time running a 35 Rem, and it looks like it is far less forgiving than 30-30 and 30-06. I am definitely learning more about the hobby with this project.

[CGT80]

Replies in red:

I think that the pressure in the primer pocket is greater than the pressure in the case with your light charge of powder and is pushing your case forward and pushing the shoulder back. Your issue is very common with rimless-bottle-neck cases when used at very low pressures and the 35 Remington with its abbreviated shoulder and thin brass is probably very susceptible to this "shrinking."

Enlarge your flash hole to reduce the pressure in the primer pocket to less than the pressure in the case and your problem will go away. I've done this for many cartridges (especially when the kids were learning to shoot) and it is an effective way to preclude your "shrinking headspace." I just finished prepping a batch of 120 Lake City 30/06 cases in this manner as even these stout cases are susceptible to "shrinking" with the very light loads that are under discussion.

This sounds like a great idea. I just don't know how big is big enough, or how big is too big. I am at 0.078" now and that is what the brass was made with. This was factory federal ammo with 200 grain bullets that I measured with a micrometer at 0.357". I did not actually open up the flash holes, so I will try that.

Over the years, I have verified this shrinking phenomenon and its cure in different rimless calibres caused by ultra-light loads using measuring tools from Mo's, RCBS and Stony Point (now Hornady). It is a repeatable experiment and is probably what is behind your problem.

I just looked closer at the cases with normal primers vs. the backed out primers. WOW!!! The shoulder is set back an 1/8" or so on the primers that backed out. I think I will scrap those.

You may also enjoy less extreme spread and a smaller standard deviation for better ballistics with very light loads using an enlarged flash hole.

As noted above, mark such cases and keep them segregated.

The second option (as you surmise) would be to increase chamber pressure and get your velocity up to about 1,300 fps or so. I am open to going hotter as well. Right now I am using plated bullets and didn't want to push them too fast, but at less than 1000 fps, I know know they will handle a hotter charge. We aren't necessarily looking for mouse fart loads, but just an economical load that is soft on the shooter. Right now the recoil is non existent.

A third option would be to use a heavier bullet sized slightly larger than your current projectile to increase pressure and still keep your velocities low... if that is your goal. I have no idea what your actual bore size is, but a .357" bullet may be a tad on the small side as most 35 calibre rifles (modern anyway) use .358" jacketed bullets and I size my 35 Whelen boolits to .359" diameter. I understand that Marlin Micro-Groove bores can be slightly larger than conventional bores and here is where that .357" diameter bullet may be a bit small if your Marlin has the Micro-Grove rifling.

I had read that the 35 Rem often want boolits bigger than 0.357", especially in the microgroove. The plated bullets matched the factory j words, so that was my easy starting point. Our goal was to get our results cheap and easy, and I have many 0.357" bullets on hand. I figured that if the pistol bullets failed, I would have to buy larger bullets or cast some boolits tailored to this gun. I am a huge fan of the NOE mold I use for my 30 cals, and I would go that route if the neighbor wants to spring for the cost of the mold. I might have loads too light and bullets too small.

A couple of other notes:

There doesn't appear to be any powder residue on your case necks, so that's a good thing and indicates that you are at least obturating your cases in a radial sense.

There was a little black soot on one side of the case necks, but it is not real dark.

Large pistol and large rifle primers are different heights with the LR primer being slightly taller. Given that, the LP primer will seat slightly deeper in the primer pocket than a LR primer. Probably not too important here, but I do note a missing primer in your LP loads. That's normally caused by excessive pressure and that's just the opposite of our discussion here. Any ideas? Loose primer pocket? Double charge?

I knew that LR and SP were the same size and that LP and LR are not the same size. I had not tried LP primers before, but I read on this forum that it worked for some when using light loads. I gave it a shot. None of the LP primers backed out. They were in the left column of the photo. The missing primer was a large RIFLE primer. The load used for the pistol primers was 5.0 grains and they all worked fine. The blown primer was also 5.0 grains, as I wanted to test both primer types with the same amount of powder. The case with the blown primer has the shoulder set back over an 1/8". The load felt like all the others, but I heard and saw the gasses come out of the primer pocket. I visually checked all the cases for powder level, so the odds of a double charge are very slim (single stage loaded).


Thanks for all the advice guys. I will bump up my powder charges and try some bigger flash holes. It sucks to ruin such expensive brass, but sometimes that is how we learn. Unfortunately, I already sized the rest of the brass, so I will have to deal with it. I am fine with keeping it all for lower power loads. There is another 70 cases prepped and not yet loaded. It does seem that the 35 Rem is less than ideal for plinking loads. I also fired one full power load, and the recoil was not nearly as bad as my 30-30 with full power loads. This is the only centerfire gun my neighbor has, so I will try to nail down a good load.

[CGT80]

Agree with RickinTN, you have a headspace issue, either created by sizing case too much or from firing cases with light loads. The tiny shoulder on the .35 Rem does not provide much support for firing pin impact. Full length size die adjustment is very critical with this cartridge. Some Marlins also have 'generous' headspace tolerance. Normally, full-length sizing for the .35 Rem can and should be avoided. You might try 'partial' sizing using the full-length sizer backed out so that the case shoulder is not moved. There are multiple discussions about concerning light lights creating 'headspace' (moving the case shoulder) issues on many different rimless cartridges on this and other forums. The .35 Rem is one of the usual suspects. Cases used for light loads should be kept separate and marked. Cases that you have already full-sized with the die touching the shellholder may need to be discarded. Enlarging primer pockets may avoid the primer backout issue, but it will hide the potential problems of 'artificially created' excess headspace.

It figures I would end up working with the PITA cartridge that doesn't follow the same sizing rules as other rifles. I do not want to trash all the brass we have for this gun, and I already sized all of it. Enlarging primer flash holes is fine with me, but how big do I go.

What are the potential problems with excess headspace, in a Marlin 336 lever gun with low power loads? Are they a real danger with the light loads, or will they just ruin the brass? I will do a little more research on my own as well, but I am all ears if want to share more info on this.

Thanks,
Chris

[pkie44]

Seat the bullets out to rifling, blow the shoulder back out.

[GooseGestapo]

Several things:
1. Load is light and as others stated, the case is being pushed forward by the firing pin, and under pressure, the case isn't being forced back against the bolt face allowing the primer to back out. I see this frequently with low pressure loads and full length sized cases. Particularily with the .30/30 and .35Rem in my l/a rifles. It's from over-sizing the cases. However, it's necessary with the lever-action rifles for easy chambering. Just don't over-do it as you already are.

2. Over length cases. You need to trim the cases.

3. Only size cases enough to easily chamber. If you keep sizing as much as the die will, you'll start having case seperations. The "crimped" case necks you see are from cases that have already stretched too much and need trimming.

Don't enlarge the flash-holes. This is fine for very low pressure loads, but if you enlarge the flash-holes and then load a "regular" load, you blow the primer and possibly damage your rifle and your face.

The primers backing out are the result of LOW pressure, not high. High pressure will cause them to fall out, but you will have long before locked up the action on a Marlin 336. If you encounter "sticky" extraction with a Marlin, you are pushing the envelope on pressures.
My experience with the .35Rem is that with "normal" powders such as IMR3031, H4895, IMR4064; you'll run out of powder capacity before you exceed allowable pressures.
Be very careful with small charges of pistol powders. It's very, very easy to double charge one. (don't ask me how I know!). I'm pretty sure that's what happened with the one with the blow primer !!!
A Lee case trimmer/pilot will set you back less than $20. I suggest you get one !! Along with a good dial vernier caliper.

[CGT80]

Thanks for the advice.

Brass was trimmed with a CTS trimmer, specs in first post. I am very careful about double charges and haven't had one so far, in 20 years. That round didn't sound any different or feel any different than the others. I would expect a double charge to have a bit more recoil or boom to it. The powder was thrown from my RCBS bench mounted powder thrower as I was loading single stage. I use a dillon 550 and 1050 for all of my own ammo, so I am used to making sure I don't do anything to end up with a double charge.

I like the sizing suggestion and I will have the rifle near by when I reset that die. I have calipers and micrometers. The trim length was from my Lyman 47th book and all cases were trimmed and deburred.

At first I thought the crimped necks were from when I seated the bullets, but I don't crimp that tight on most ammo and then it dawned on me. The brass was sized (too much) and then trimmed to 10 thousandths under max. It seems to me that the COAL was OK but the neck was too long, due to the shoulder being bumped down. The light loads didn't keep the brass to the rear of the gun.

It is time to up my loads and watch the shoulders. I will scrap those that backed the primers out as the shoulder is set back too far for comfort.

[BCRider]

I wonder if the "O-ring" or "rubber band" trick could save those brass? This is the one where you slip a tight fitting small size O-ring around the rim groove which then holds the head back firmly on the bolt face. If this works right you can fire form the cases out again even just with a charge of fast pistol powder pushing a wad of filler material such as cream of wheat or oat bran. I had excellent results doing this with my 48-55 brass using 14 gns of Unique under a fill of CoW with a toilet paper wad to hold it all in place. I don't see why this same trick would not work for saving your scarce .35Rem brass.

The only hitch is that the resistance of the rubber band or O-ring might require you to single load the casings and force the action to close against the compression of the rubber.

Beyond that I think the guys are right in that the case pressure isn't enough to kick the casing back. So either more powder is needed or a switch to a faster pistol powder so it ramps up the pressure to some higher peak value. The use of small amounts of faster pistol powders is pretty common in similar light plinking loads I've seen in other threads. If the Red Dot you're using qualifies I apologise for this last bit. I'm not that familiar with the "Dot" powders.

Enlarging the primer flash holes by a little would help with this as well. Just don't go crazy. Remember that since the area of a circle is related to the square of the radius change a few thou bigger drill gives a lot more area increase then you might realize.

I'd also avoid the Magnum primers since those create a lot higher primer pressure. That isn't helping anything in relation to these issues.

[CGT80]

I wonder if the "O-ring" or "rubber band" trick could save those brass? This is the one where you slip a tight fitting small size O-ring around the rim groove which then holds the head back firmly on the bolt face. If this works right you can fire form the cases out again even just with a charge of fast pistol powder pushing a wad of filler material such as cream of wheat or oat bran. I had excellent results doing this with my 48-55 brass using 14 gns of Unique under a fill of CoW with a toilet paper wad to hold it all in place. I don't see why this same trick would not work for saving your scarce .35Rem brass.

The only hitch is that the resistance of the rubber band or O-ring might require you to single load the casings and force the action to close against the compression of the rubber.

Beyond that I think the guys are right in that the case pressure isn't enough to kick the casing back. So either more powder is needed or a switch to a faster pistol powder so it ramps up the pressure to some higher peak value. The use of small amounts of faster pistol powders is pretty common in similar light plinking loads I've seen in other threads. If the Red Dot you're using qualifies I apologise for this last bit. I'm not that familiar with the "Dot" powders.

Enlarging the primer flash holes by a little would help with this as well. Just don't go crazy. Remember that since the area of a circle is related to the square of the radius change a few thou bigger drill gives a lot more area increase then you might realize.

I'd also avoid the Magnum primers since those create a lot higher primer pressure. That isn't helping anything in relation to these issues.

Red Dot is pretty fast, but not the fastest. Bullseye is even faster and trail boss is very fast from what I have read. Trail boss is a low velocity powder, but high pressure. It might be a good fit for this cartridge. I use it for light 460 mag pistol loads and have used it in 30-06, but Red Dot is cheaper and I have lots of red dot. I also have some bullseye, but it seems like there would only be a pinch in a case that big. I have only used it for 38 spl and maybe 45 acp, so that would be new territory for me.

I will try some standard large pistol primers. It makes sense to not use a primer that has more force than needed and I would think the magnum primers may have more force if they burn hotter. The O ring trick is a new one to me. I will have to research that some more. I have never done anything like that. I checked the inside of the cases for lines near the base of the brass. I used a bent paper clip and a bright led light. They look clean and normal. I also compared the one round (the case) of factory ammo that I shot to the cases from my light loads. The shoulders are the same distance from the case head on the brass that did not have primers back out.

Great tip on the flash holes, as I did not think about that relationship. I also only found one value when looking for others that opened up flash holes. I would be completely guessing on how much to open them.

[1johnlb]

Slugg your barrel, use properly sized boolits that fit the throat. Lee molds are to cheap not to do it right.

Use standard primers/for reddot LP is fine/ mag. primers is overpressure in the pocket for that 6.0 RD load

Then increase your reddot load/until you have proper sealing

don't get lost trying to fix problems that are easily fixed by good reloading techniques.

[BCRider]

I've noticed how Trail Boss can often give lower comparable velocities with surprisingly high pressures in the rifle loads. So you may be onto something there.

The O-ring or dental rubber band trick is detailed for use on rimmed cartridges to aid in fire forming so the casing doesn't stretch just ahead of the head as they normally try to do. For things like Mosin Nagants and Lee Enfields it involves the right size O-ring or dental brace rubber band that goes on ahead of the rim and holds the casing back tight against the face of the bolt. Essentially it provides a zero headspace fit for the first shot and from there you dedicate those brass to that rifle for ever after.

In the case of a rimless cartridge this may not work unless the bolt face is recessed and the groove does not extend into the chamber. But if this is the case then the rubber band or O-ring will hold the casing back from going in too far and so the head is very close or held against the bolt face. Firing the ammo at this point will chamber form it to that rifle and make even that choked mouth casing useable again.

[CGT80]

Tonight, I made up more test loads. They all have winchester large pistol primers. For Red Dot, I started at 7.0 grains which was my max tested load last time (last time was LRP with that load), then I have 8.0, and then 9.0. Trail Boss might be the ticket so I worked up two loads.......8.5 and 10.0. 100% of my case capacity with this bullet would be 12.2 grains, and 8.5 is 70% which is the suggested starting load. In my 460, I run 10.0 grains with a 270 grain boolit and I can ping a 12" plate at 100 yards, offhand, with the iron sights. I am more consistent if I use a sand bag to rest on. More powder did not prove to be better in the revolver, as I had tried up to about 14 grains IIRC.

Those bad cases are sitting on my bench, just in case I figure out that I am able to fire form them. The suggestion of using a lee mold is a good one too. I would much rather use an NOE, but if my neighbor pays for the lee and I am only doing small runs, then it would be fine, and much easier on his wallet. It will be interesting to see what he thinks of the rifle with the reloads and if he ends up shooting it often. If he catches the bug, then I will probably recommend a different gun................I have been tempted to get a Rossi 357 stainless lever gun and it would probably be a good fit for the neighbor for the same reasons it appeals to me.

Hopefully I will make it to the range during the week to run the test loads and update this thread.

Chris

[MostlyLeverGuns]

While not normally recommended, lightly lubricating cases for LIGHT reloads might reduce primer protrusion. The case expands to grip the chamber when fired. If lubricated, the case can move or 'slide' rearward when fired. Reducing or eliminating the case shortening effect. I normally will lubricate cases when fireforming to insure complete expansion in the chamber. There are many who will wildly object to this. Varmint Al addresses this issue from an engineering standpoint at www.varmintal.com. Carefully enlarging the flash hole sounds good. Many of the 'green' or lead-free cartridges have large flash holes. Reloading advice has mostly been to ignore it in the handgun cartridges.

[1johnlb]

Look at the case mouths, they clearly are being shoved in the throat of the rifle from undersized boolits. If they go any farther you'll be able to see rifling. Just my 2cents. Use the correct size boolits until brass is formed.

[fouronesix]

To fire form new brass or good used brass that hasn't been unduly stretched for that rifle, you can seat a fairly hard cast bullet long and crimp it in place over a safe medium pressure load. When the cartridge is chambered, the bullet will jam some into the bore and hold the cartridge head firmly against the bolt face through the entire firing cycle. That will form the shoulder correctly to the chamber of that rifle. Then back the sizing die off to avoid touching the shoulder but far enough in so the case is sized enough for easy chambering in that rifle. Sometimes however that may require a small base type die- depending on the specs of the sizing die compared to those of the rifle chamber.

I would stick with standard large rifle primers and standard flash holes- but that's just my opinion. And don't feel alone with the 35 Rem, the 35 Whelen will show the same thing with light loads. Both cartridges share the same weakness in headspace control. The long term solution is re-reaming to improved shoulder- but's that another topic.

[CGT80]

This afternoon I made it to the range.

Success!!!

The first test loads (that did not have primers back out) did not have shoulder set back. That empty brass fed right through the rifle, so I knew I didn't need to set the shoulder back more. I moved the sizing die up 1/8" of an inch or so from touching the shell plate, and sized them. It sized the necks most of the way to the shoulder. I checked the length and they had shrunk 2 thousandths from what I trimmed to before (probably necks moved back just a hair. I then loaded them the same as before, but all with large pistol primers.

Loads were 7.0, 8.0, 9.0 of red dot and 8.5 and 10.0 of trail boss.

63 rounds in all, with the same bullets, but all LPP. None of them showed shoulder set back or primers backed out. The necks were fairly clean. I changed the front sight to a shorter one and sighted in. I was able to consistently hit an 8" steel plate at 100 yards with open iron sights, from the bench, with a breeze and the sun in my eyes. The shoulders looks a bit more filled out this time, like they may have fire formed a bit. It will be interesting to see how the length is now. I did not touch the primer pockets or flash holes.

The first test loads were a 100% test with the LPP. That seems to be the key. 8.0 of red dot worked well, but 9.0 was fine as well. Trail boss actually put me in the dead center of my bullseye with one shot, but I only had 10 rounds of each TB load, and it could have been a fluke.

I need to clean the gun and see how the barrel looks. The muzzle end looks clean. I didn't bother with setting up the chrono today.

For now, I will load the copper plated bullets with 8.0 of red dot and LPP. My neighbor can try it out and see how he likes it, and then we can go from there.

I know that I could go further with making better loads for this rifle, and I could use more appropriate boolits, but this will probably be a low volume plinker and I have many 357 bullets that I don't use. If it was my gun, I would get a custom mold and sizing die and try for even better accuracy.

The Marlin 336 functioned great. I can drop a round in and it chambers every time. When I open the bolt slowly, the shell sits at a 45 degree angle to be picked out by hand. It works great for not chasing brass. The gun I use for competition is a Win 94 made in the early 70's. It is a top eject, so I have to work a bit more to grab the brass, and it is a more of a pain to load the magazine. I am half tempted to shoot the next match with the marlin, but it is also heavier than the Win.

[RickinTN]

Glad you're getting things working your way.
"To fire form new brass or good used brass that hasn't been unduly stretched for that rifle, you can seat a fairly hard cast bullet long and crimp it in place over a safe medium pressure load. When the cartridge is chambered, the bullet will jam some into the bore and hold the cartridge head firmly against the bolt face through the entire firing cycle. That will form the shoulder correctly to the chamber of that rifle. Then back the sizing die off to avoid touching the shoulder but far enough in so the case is sized enough for easy chambering in that rifle. Sometimes however that may require a small base type die- depending on the specs of the sizing die compared to those of the rifle chamber.

"I would stick with standard large rifle primers and standard flash holes- but that's just my opinion. And don't feel alone with the 35 Rem, the 35 Whelen will show the same thing with light loads. Both cartridges share the same weakness in headspace control. The long term solution is re-reaming to improved shoulder- but's that another topic."

This post by Fouronesix is dead-on as far as a way to salvage the brass which was over-sized for the rifle.
Good luck, and I hope you and your neighbor enjoy the rifle,
Rick