made a rifle OAL gauge and getting big numbers..I think?

[guy_with_boolits]

AR 16" barrel .223/5.56

In an effort to improve accuracy of the ammo I've decided to control shoulder bump and bullet jump. The measurements seem a bit...big.. but heres what I got, does this sound right?

I adjusted the FL sizing die to achieve a -0.004" shoulder bump compared to a fire formed case.

Next was bullet jump. Using the OAL gauge I made, and a 50gn lead-free varmint grenade bullet, I measured COAL with the bullet to the rifling. (A case with -0.004" shoulder bump was used)

I got a 2.310" COAL! Even if I wanted a 0.015" bullet jump thats 2.295" COAL which wont fit the magazines and is significantly longer than the recommended load data for this bullet, which is 2.200".

To reality check things, I did tests with the COAL at 2.305" and 2.320". At 2.305" the bolt locks in place with zero effort. At 2.320" it takes some slight finger pressure but it locks, although the bullet (when marked with a sharpie) definitely has rifling marks on it.

So...what do I conclude from all this? My goal is to make accurate ammo. Should I modify a magazine to fit these at 2.315" COAL and then develop a load? Is that even realistic at that COAL? I dont mind single-loading each round if need be.

note: the OAL gauge I made is pretty self explanatory. If you have a home machine shop its a fun project but otherwise I'd suggest just buying the $40 hornady OAL length gauge and the associated modified case

[M-Tecs]

Load them to max. mag. length and test them for accuracy. Do the same for max chamber length. You will have to single load but test for accuracy. Some loads and bullets are very tolerant of large bullet jumps.

I have a very well used Krieger barrel on my primary prairie dog AR. It's still holding 3/8 MOA with an insane amount of bullet jump.

[guy_with_boolits]

Load them to max. mag. length and test them for accuracy. Do the same for max chamber length. You will have to single load but test for accuracy. Some loads and bullets are very tolerant of large bullet jumps.

I have a very well used Krieger barrel on my primary prairie dog AR. It's still holding 3/8 MOA with an insane amount of bullet jump.

dam okay thanks..so why did you end up keeping the large bullet jump? did you notice differences between max mag length and near max chamber length?

according to this article, some bullets will have a shape that hits the rifling much sooner and would let me load to mag length but still keep bullet jump to minimum

http://www.mssblog.com/2017/08/17/re...tter-part-one/

he specifically mentions this hornady 52gn boat tail hollow point as being 20 thou into the lands at max mag length https://www.midsouthshooterssupply.c...atch-100-count

[M-Tecs]

dam okay thanks..so why did you end up keeping the large bullet jump? did you notice differences between max mag length and near max chamber length?

That is easy. Cause it still shoots to my accuracy requirements despite an extremely high round count. When I initially set the barrel up I had the gas port extended 2 inches with the intent of setting it back but the accuracy never dropped off. Why would I replace it when it still is fully serving it's intended function? With the bullets I use 350 yards is about as far as I care to shoot pararie dogs at. When I start getting unexplained misses or poor hits it will get replaced.

If I want to shoot further I switch to a bigger calibers than the .223. I try to maintain a 75% kill ratio. On windy days that's not realistic but on days when the wind is under 11 or 12 miles per hour it is realistic since you still can read the mirage.

I do my own work so the cost to rebarrel is less for me but I still shoot all my barrels to the end of there service life. For match rifles that's when they stop holding elevation at distance. They will cost points at 600 yard but still group well at 300 yards. Once they are not usable as a match rifle they get used for prairie dogs or something that doesn't require extreme accuracy.

In the case of my primary prairie dog AR rifle it mostly has seen 40 gr. V-Max with maybe 20% 55 gr. V-Max over H335 or CFE223. Neither bullet would touch the lands when new but it would hold between 1/4 and 3/8 MOA for 5 shoots at 200 yards. I use the same reamer I use for service and match rifles so it's throated for longer bullets. It's still holding 3/8" at 200. That being said it's way way past holding elevation at 600 yards. It has a 9 twist so that too slow for the heavier vld type bullets that are designed for the 600 yard plus shooting. The VLD's tend to be more sensitive to bullet jump.

Glen Zediker is a true expert. I have most of his books and I met him once briefly at Camp Perry. He knows his stuff and his advice is always good but in the end it is advice and recommendations. Actual testing is the final word.

On my match rifles I do chase the lands as they advance. On varmint rifles I normally don't unless I note a decrease in accuracy. I shoot long range competitions but I have never got into the ultra long range hunting or varminting.

Some more interesting reading here: https://precisionrifleblog.com/2020/...est-practices/

[guy_with_boolits]

okay I loaded about 30 as follows:

COAL 2.295 +/- 0.002"
same headstamp once fired brass (WOLF headstamp)
no annealing..just FL sized them to -0.005" +/- 0.002" shoulder bump then chamfered the inside and outside.
brass was sorted to 1.750" to 1.760" length
bullets weight sorted to 0.1gn (50gn +/- 0.1gn)
powder was just delivered by my lee disc measure...that seems to be a weak link in my loading setup..I have no way to confirm the weight of each charge..maybe I should get a trickler? or some other strategy? I dont mind doing things slow while I develop this. Maybe I should just get a funnel and pour in powder very slowly by hand while its on the scale.

I single loaded each, by dropping them into the space above the magazine, tilting the rifle so they would fall into the chamber, then riding the charging handle until the ejector pin was pushed up against the head. Then I would tap the forward assist once or twice so the round would get locked into the bolt.

At 50 yards it was a 2" group with no flyers. At 100 yards it was more like 4".

I chronoed a previous load using these bullets (50gn varmint grenade) and they were only in the 2700 fps range. Now the COAL is almost 0.100" longer so I got to think they are going quite slow. I would think the faster they go the more stable they get. However with H335 I cant drop the max load without slightly going over it with my Lee disc..instead of 24.4 I probably drop 24.6 or so. I am using a 1:7 twist 16" barrel so at least thats in my favor.

Should I switch powders? I have the following, which would be a better choice?

Reloder 7
H335 (currently using)
Accurate 2230
Power Pro Varmint

[M-Tecs]

Do you know what level of accuracy your rifle is capable of? What do you have for sights? What are you capable of?

With a decent scope and rest the groups should be significantly better, however, with a large red dot that's not bad. Even the really low cost barrels tend to shot well. Sometimes really well but once in a while you will find one that doesn't shoot well. Also is the barrel in a float tube handguard or standard GI configuration handguard?

H335 is a great powder for the .223. You're using the Barnes data and they are light on their max charge weights compared to most other sources. Of course different bullets produce different pressures. The VG's are a hollow-cavity, flat-base bullet features a copper-tin powdered metal core surrounded by a guilding metal jacket. If they are like there TSX's they may like more jump not less. Barnes recommends between .050" and .250" jump for the TSX's

Load or purchase a box ammo with 69 grain Sierra Match King - HPBT and establish what the gun is capable of. Next would be trying a different bullet. I have zero experience with the VG but I have 50 and 52 grain bullets that shot great out of a 9 twist but they would not tolerate the 7 twist barrels.

I have never had an issue with either the 40 - 55 grain Hornady V-Max's or the Nosler Ballistic tips in the same weight regardless how hard I pushed them or how fast I spun them.

https://www.barnesbullets.com/load-data/

1. Where do I seat the TSX, Tipped TSX and LRX bullets?

When loading a Barnes TSX, Tipped TSX or LRX bullet, your rifle may prefer a bullet jump of anywhere between (a minimum of) .050” up to .250” or more. This distance off the lands (rifling), aka "jump" may be limited to the rifles throat length, magazine length and bullet length.

When selecting the cartridge overall length (COAL) we recommend starting with a minimum “jump” of .050” off of the lands. You can test different seating depths and find a “sweet spot” that your particular firearm prefers. We suggest working in at least .025” increments as follows seating the bullet deeper to allow a further jump. Your test plan could look something like this:

1st group- .050” jump
2nd group- .075” jump
3rd group- .100” jump
4th group- .125” jump
5th group- .150“ jump
6th group- * see below

This length can be determined by using a “Stoney Point Gauge” or other methods. You do not have to seat the bullet at, or on one of the cannelure rings. Remember there are many factors that may control or limit the seating depth for your application. You may find that you need to start at around 0.150” off the lands and are not able to get any closer due to limiting factors including proper neck tension and magazine length.

*In rifles that have long throats you may be limited on how close you are able to get the bullet to the lands. In these instances, it is not uncommon to find the best accuracy with a jump of .200” or more.

[guy_with_boolits]

Okay tested two loads today:

A- the one Ive been discussing in this thread: 50gn VG, H335, 2.295" COAL, .005" shoulder bump, but this time about 24.4gn of H335 instead of 23.5
B- a totally different load, 55gn FMJBT, 20.8gn RL-7, 2.250" COAL, .005" shoulder bump, range pickup lake city brass trimmed to 1.748"

I was only able to chrono one of each.

A- 2894fps
B- 2743fps

I was able to try A at 50 and 100yds, but B only at 50yds.

It seems B is the superior load looking at the group. About 1" at 50 yrd and basically circle. I think that might be at least 50% me.

A at 100 yards is about 5 MOA. But at least its in a basically straight vertical line. Makes me think its all powder variation and/or neck tension. Does that seem right?

Where do I go from here? Seems like that RL7 load deserves a little more speed and/or some playing with the COAL and shoulder bump, although I dont have much to work with given the bullet is so short.

[44magLeo]

You mention the Lee disc powder measure. Those are fine if your load works with the disc. If not then you need an adjujstable measure. For Lee fans there are the two versions of the PPM. One all plastic the other has alloy parts and a better micrometer for adjustment.
Other manufacturers make great measures too. RCBS, Lyman, My choice. Hornady. Pick one. These will let youuse loads between the holes in the disc.
Leo

[44magLeo]

Had another thought, You could ream out the hole in the disc a bit at a time to increase the charge. If your measureha the stacking kit you only need to adjust the lower disc. Just go a bit at time and check the charge It can go quick, so as yu approach the charge you want, reduce how much you remove from the cavity. Easy to go to far. Then you have to shim it back out.
Speaking of shimming, you could try shimming down from the hole that is too big by appling lain old scotch tape in layers to the inside of the cavity. Thid way you are not permenently altering the disc.
Leo

[44magLeo]

On your chambers throat area I think most manufactures go a bit long here. This no way a factory load will hit the rifling and produce excess pressure.
I'm a bolt gun kinda fellow so my 5.56/223 rifle is a bolt gun. A Stevens 200.
The chamber is cut with a long throat. I dont recall exactly and don't feel like looking it up but about 1/4 from the mouth of the case is were the rifling starts. Some very light weight bullets can't be seated out to touch the rifling. Get up to 50+ grs and they are ok.
The action and magizine on this rifle is a 308 length. The bolt has a spacer on it to limit the length of movement to closer fit the 223 length cartridge. The magizine is blocked off the same amount. Even with this I can seat bullets out to the rifling and still fit the mag. Some guns the chamber is cut long and has a shoter magizine and won't let you seat that long.
My 223 has a 1-12 twist so anything longer than a flat base 60 gr bullet won't stabilize. I bought a box of the 62 gr FMJ boattails. At 100 yards thier was evidence of keyholing. Not completely sideways but diffently ovaled holes.
Thats ok. I'm not a long range shooter with it anyway. Out to 2 or 300 yards is about it. My 6.5 Creedmoor is for the longer ranges at paper. For longer range hunting the 280 rRemington works well out to 3-400 yars. Any farther than that and I move closer. If I won't or can't move close I don't take the shot.
Leo

[David2011]

Could it be possible to overthink bullet jump? I’ve explored it a little but hit some dead ends. I bought the wrong barrel when I built my 6.5x55 and only got a 10” twist so I’m limited to 120/129 grain bullets. The reamer I used was a standard SAAMI spec one that will accommodate the very long 170 grain military bullets. There’s no way to get the lighter bullets close to the rifling. It will still group in the low .300s with the right load.

I never gave bullet jump a second thought for an AR. I have one that shoots 3”-4” patterns at 100 yards with every factory load I’ve tried. With handloads using Sierra Match King 52 or 53 grain or 50 grain V-Max it shoots .300-.350 at 100 and 3/4” at 200 yards loaded to SAAMI OALspecs.

[garandsrus]

As was mentioned, try a better bullet to see what the rifle is capable of. The Sierra 69gr is one of the most accurate 200yd bullets.

There are some bullets that just aren’t very accurate. Most FMJ bullets are not considered target bullets.

[guy_with_boolits]

okay i got my hands on some 69gn and 77gn matchking bullets

still trying to hunt down new brass

but I suppose my once-fired lake city brass isnt so bad for the moment

[guy_with_boolits]

well turns out with a COAL of 2.250" bullet jump with 55gn FMJBT is 0.113" in my rifle

which puts the case mouth right below the cannelure

that might be the limit of COAL since pushing the bullet out further seems like it would mean some neck isnt grabbing bullet

what are thoughts on that?

[Mk42gunner]

okay I loaded about 30 as follows:

COAL 2.295 +/- 0.002"
same headstamp once fired brass (WOLF headstamp)
no annealing..just FL sized them to -0.005" +/- 0.002" shoulder bump then chamfered the inside and outside.
brass was sorted to 1.750" to 1.760" length
bullets weight sorted to 0.1gn (50gn +/- 0.1gn)
powder was just delivered by my lee disc measure...that seems to be a weak link in my loading setup..I have no way to confirm the weight of each charge..maybe I should get a trickler? or some other strategy? I dont mind doing things slow while I develop this. Maybe I should just get a funnel and pour in powder very slowly by hand while its on the scale.

I single loaded each, by dropping them into the space above the magazine, tilting the rifle so they would fall into the chamber, then riding the charging handle until the ejector pin was pushed up against the head. Then I would tap the forward assist once or twice so the round would get locked into the bolt.

At 50 yards it was a 2" group with no flyers. At 100 yards it was more like 4".

I chronoed a previous load using these bullets (50gn varmint grenade) and they were only in the 2700 fps range. Now the COAL is almost 0.100" longer so I got to think they are going quite slow. I would think the faster they go the more stable they get. However with H335 I cant drop the max load without slightly going over it with my Lee disc..instead of 24.4 I probably drop 24.6 or so. I am using a 1:7 twist 16" barrel so at least thats in my favor.

Should I switch powders? I have the following, which would be a better choice?

Reloder 7
H335 (currently using)
Accurate 2230
Power Pro Varmint

Please tell me that you have a scale and I am reading that sentence wrong. Without a scale you are guessing (a very dangerous thing to do) and a trickler is not needed anyway, a teaspoon or dipper works just as well plus it is quicker to use.

Robert

[guy_with_boolits]

Please tell me that you have a scale and I am reading that sentence wrong. Without a scale you are guessing (a very dangerous thing to do) and a trickler is not needed anyway, a teaspoon or dipper works just as well plus it is quicker to use.

Robert

yes I have a scale. the lee auto disc powder measure seems to be dropping 20.8 +/- 0.3 grains with RL7...I cant weigh every drop but if I weigh 5 in a row I see that variance. a trickler would let me make each load identical to the limit of the scale resolution

today I tested two loads:

55gn FMJBT in both

RL-7 in both

lake city brass in both (probably twice fired now)

shoulder bump 0.005" in both

load A: COAL is 2.250", powder around 21.4gns but again I cant be sure..I was able to get it to dump higher by tapping the powder container on the LEE auto disc a few times for each load buts not a precise method..this is why I want a trickler.
chronod
2792
2765
group size just under 3MOA at 90yards...I am definitely a big part of that..I'm getting better but I'm sure I'm adding at least 1 MOA to the group size

load B: COAL is 2.340", making for a 0.020" bullet jump
group pretty bad at 50 yards..huge flyer, but I only made 5 rounds of this load so I think I need to try it again with more
chronod
2690 <----yikes
2873
2843
very weird this load has higher fps than load A, which should have more powder, and also a much shorter COAL..any ideas how to explain that?

Something I had hoped to do here was bump the speed up to 3000+ fps but it looks like I wasnt able to. My lee disc setup either needs double discs or I need to trickle to get more powder in the case.

My next batch will be with trickled/hand poured powders within 0.02gn of each other, and I'll make 50 rounds of each and get a much clearer idea of which one is superior

My sierra matchking 69gn and 77gns will be here in a week or so and then I'll see how those go too

[44magLeo]

Had a thought. For many of the longer range target shooting they use the long high B/C bullets. To get the maxvelocity out of this bullets they seat them out so very little of the bullet is in the case. This leaves a cartridge that won't fit in the mag. This is not a problem because on these log range targets they have time to single feed rounds into the chamber.
Barrel throats are cut so thus can be done without isses. As fedding from the mag isn't an issue.
Your barrel may be cut this way.
For most other shooting that least .1" better group isn't has imp[ortant so loading to the maxlength of your mag works ok.
From what I under stand somemags are made longer than others. I can't tell you which are which but I assume it could be researched.
Leo

[uscra112]

On your chambers throat area I think most manufactures go a bit long here. This no way a factory load will hit the rifling and produce excess pressure.
I'm a bolt gun kinda fellow so my 5.56/223 rifle is a bolt gun. A Stevens 200.
The chamber is cut with a long throat. I don't recall exactly and don't feel like looking it up but about 1/4 from the mouth of the case is were the rifling starts. Some very light weight bullets can't be seated out to touch the rifling. Get up to 50+ grs and they are ok. f I won't or can't move close I don't take the shot.

You've got one too? Ditto on the long, long throat. I've been assuming mine had been reamed, (bought it used). Shoots the lights out with 55 grainers anyway, because, I think, the cylindrical part of the throat is only .2245 (from a cast.) In the '50s they called this "freeboring", done to reduce pressures in some of the radical wildcats of the day. It's not a benchrest competitor, but darned good for a cheap rifle. Only thing I've done with it is to scrape the plastic stock here and there to improved the bedding.

So IMHO the O.P. should not get wrapped around the axle over his OAL until he starts using bullets long enough to touch the leade.

[uscra112]

BTW I did test RL-7 loads up to 22 grains with the 55 grain softpoint I use, but a Varget load at 2800 fps is more accurate. No help for the O.P., Varget is out ofstock everywhere just like everything else, I expect.

[jetinteriorguy]

Please don’t be offended by what I’m about to say. First thing, I’m assuming you’re a fairly new hand loader and am going to make my suggestions based on this assumption. You seem to be randomly picking loads which I’m assuming is based on only having a Pro Disc powder measure. Not a good method, you need to get an adjustable powder measure, and then start at minimum loads and work your way up to maximum loads based on good published loading data. Your bouncing around using whatever bullet gets your attention, pick one and work with it using solid well known methods and if it doesn’t work well move to the next one. I’d suggest finding an experienced person nearby to mentor you if possible, or at least get a couple good manuals and read them thoroughly until you understand the basics. You seem to be focusing on fine tuning loads by experimenting with seating depth when you haven’t even established a good basic load by first finding a good powder amount. If you keep on as you’re doing now your only going to waste a lot of time and components and never learn good basic methods. If cost is an issue I’d suggest a Lee PPM or for a little more money the Lee Deluxe PPM is as good as any powder measure I’ve ever used, and I’ve used a few different ones over the years.