1:10 twist .308 cast @ 2605fps at 500 yards sub 2 MOA five shot group.

[waco]

So my brother and I went out shooting this morning testing more high velocity cast .308 bullets.
I had some mixed results. Some of the 30 XCB bullets @ 2530 did okay until the barrel got hot then the shots started to wander.
These were 166gr bullets sized to .311" and lubed with 2500+ and a coat of BLL. These were loaded with 46.5gr H414 @ 2530fps

The second attempt was 47.5gr at 2605fps and I was able to get a sub 2 MOA five shot group.
https://www.youtube.com/watch?v=l9VDouNYi7A

[Tom_in_AZ]

Wow!


Sent from my iPhone using Tapatalk

[Time Killer]

Nice Shooting

[Hogdaddy]

Great shooting,, KEEP UP THE GREAT WORK ; )

H/D

[44Blam]

Inspirational!
Nice shooting!

[s mac]

Enjoy your videos and your efforts. Good job Waco.

[waco]

Thanks guys!

[popper]

You ever get to try the alloy & boolits I sent?

[Echo]

Out-Flamin'-Standing!!!

[waco]

You ever get to try the alloy & boolits I sent?

I did. I was only running it around 2260fps with RL15
They shot pretty good.

[toallmy]

Inspiring to say the least .

[dverna]

I cannot shoot like that with jacketed. At 500 yards, the wind will get to me, even if the gun and load are capable. A 10 MPH wind will give over 2 ft of windage. Great shooting waco.

[waco]

Thank you for the kind words Don.

[44Blam]

Hey Waco, what mold did you use?

[waco]

hey waco, what mold did you use?

noe 30xcb

[megasupermagnum]

noe 30xcb

I assume you have tried a number of different kinds of bullets. Why do you like the tapered nose style so much? I can understand the shortcomings of a bore rider for high velocity, but how about a full body bullet like the Loverin design?

[waco]

I assume you have tried a number of different kinds of bullets. Why do you like the tapered nose style so much? I can understand the shortcomings of a bore rider for high velocity, but how about a full body bullet like the Loverin design?

I might try something similar with the NOE copy of the Saeco 315

[megasupermagnum]

It's all theory, but if the limiting factor with the velocity of cast bullets is the alloys ability to hold rifling, I would think a bullet that is all bearing surface would hold the best. Maybe not. I now want to try some higher velocity bullets in my 308 Winchester 1:10" twist. I'll see how far the Lee 309-170-F will hold up. I was thinking a 200 grain bullet with just enough lube, all bearing surface, and a very short nose should be the best you will get. I've got one drawn up. I don't understand why the Loverin designs have the tiny drive bands, especially since so many recommend only filling half with lube. I would think 3 small lube grooves, with hefty driving bands would be a better way.

[waco]

I’m not sure. This is what has brought me success. The mold and alloy used was suggested by a few other people. 30 XCB cast from a 90/6/4 alloy. Pb, Sb, Sn and water dropped for a bhn of approximately 18.
230360
I sized these to .311" and the are lubed with Lar's 2500+ and have two thin coats of Ben's liquid lube over them.

[Larry Gibson]

megasupermagnum

"It's all theory, but if the limiting factor with the velocity of cast bullets is the alloys ability to hold rifling"

That is not the primary limiting factor, but it is one of the very important factors.

"I would think a bullet that is all bearing surface would hold the best."

It's not that the most bearing surface holds the rifling better but one of the longer the bearing surface vs OAL of the bullet the more concentric the bullet stays. Understand the bullet rides a layer of lube down the bore. Thus the bullet is swaged down to less than groove/bore diameters....by as much as .003 - .005".

"Maybe not. I now want to try some higher velocity bullets in my 308 Winchester 1:10" twist. I'll see how far the Lee 309-170-F will hold up."

You will find that bullet, with it's long unsupported nose, will have a much lower RPM Threshold than does the 30 XCB bullet.

" I was thinking a 200 grain bullet with just enough lube, all bearing surface, and a very short nose should be the best you will get."

That would be good but it still needs multiple narrow and shallow grooves that are all lubed (similar to the grooves on the 30 XCB). The drive bands should be at least as wide as the XCBs also. Additionally the GC should not extend below the neck into the case (at least the top of the GC should remain in the neck). Thus such a bullet loaded as such in a 308W case would require a long throat in the chamber. The throat diameter should not be larger than .3105 with a .308 grove diameter barrel. The bullets should be sized to not smaller than .310 for a snug fit in the throat. That would give the bullet almost full support its entire bearing length.

"I don't understand why the Loverin designs have the tiny drive bands, especially since so many recommend only filling half with lube. I would think 3 small lube grooves, with hefty driving bands would be a better way."

The Loverin designs were done back in the day before we had the modern efficient lubes we have today. The concept with the lubes they used was a lot of lube was needed and the Loverins were never intended for true HV. However. I have pushed the 311466 Loverin cast of #2 alloy upwards of 2400 fps with 2 moa or less accuracy in a 10" twist .308W. In a 12" twist 2500 - 2600 fps with sub 2 moa accuracy was done and in a 14" twist .308W 2700 - 2800 fps with sub 2 moa accuracy was also accomplished. I'm talking 10 shot groups BTW.

I was instrumental in the design of the NOE 30 XCB cast bullet. The concept was to design a cast bullet to just fit the neck length of the 30-06 neck from the base of the case neck to the chamber leade, to have 65 - 68% bearing surface (same as the 311466) and to have minimal non bore rider nose length and to have narrow shallow lube grooves. The resulting NOE 30 XCB bullet has proven excellent at velocities as high as 3100+ fps and as low as "normal" cast bullet velocities. It is especially great when used in the cartridges it was originally designed for; the 30 XCB (30x57) and the 30x60 XCB. Fortunately, it also shoots extremely well in most .308Ws, especially if they have a bit of throat length allowing proper seating of the bullet.

Waco is demonstrating how with a properly designed cast bullet in a good rifle, using proper loading techniques and a slow burning powder that the RPM Threshold can be pushed up.

Here's an 11 shot sub moa group (5.9") I shot with the 30 XCB out of the 30x60 XCB cartridge at 600 yards. The velocity was 2900 fps.

230362

[popper]

One reason I sent Waco some 31-165c slick side FP GC I push hard in the 308w. The BC isn't for long range .

[waco]

LOL!!!!! I'm not going here again!!!! I know you were a big part of the design of the 30 xcb mold. You have told people for a LONG time that you can not get accurate (sub 2 MOA) loads with a fast 10 twist barrel at distance with high velocity.

500 yards. 2600+fps. Sub 2 MOA accuracy. Video proof. I don't care ONE BIT what you can do with 1:14-1:16 twist.
My point is you CAN do it with a 10 twist. No RPM threshold. At least I have not hit it yet.

Stellar groups and results Larry at 600 yards with your 1:16 twist custom rifles. I commend you. Well done Sir. I take nothing away from you.

I'm just showing everyone it can be done with a bone stock 10 twist at 2600+fps as well.

Happy shooting my friend.

Walter

[Larry Gibson]

waco

Perhaps you failed to notice my post was addressed to megasupermagnum. My post addressed the points/questions he raised. Whether or not you care "ONE BIT" or not is not relevant to my response to him. However, you certainly are entitled to your own opinion, just no need to denigrate someone else to make your point.

You are also still wrong. I have consistently told everyone for numerous years on this forum how to push the RPM Threshold up. The RPM Threshold is not a "limit" but can be moved up or down by using different components and bullet designs. On your previous 500 yard thread(s) I again explained how. The loads you used on those threads did, in fact, hit the RPM Threshold. That's why the load used then gave 4 - 5 moa. In this test you changed to a different, slower burning powder than previously used with a slower time/pressure curve which, just as I've consistently said to do, is a change of components. You also changed to an alloy closer to what has proven to be best at HV. Doing such it appears you have met with success with the load and components used in this thread. It indeed appears you have pushed the RPM Threshold up quite a bit in your 308W with 10" twist barrel, well done. In the previous post my only mention of you and your shooting in this thread was a compliment on how you are demonstrating how the RPM Threshold can be pushed up.

As to the information I posted to megasupermagnum, it applies to the bullet designs he mentioned, particularly the 311466 Loverin design in a 10" twist barrel and also in other twists. Those are not the NOE 30XCB you used. My explanation to him was to lend back ground information to the suggestions for his 200 gr bullet design and his questions regarding the 311466 Loverin design.

Question for you; do you think my milsurp F.M.A.P. M98 action with a Midway special $89.95 24" sporter contour Adams & Benet barrel in a sporter wood stock is the equal of your "bone stock" M700 heavy barrel rifle?

[Nrut]

Great job to both you and your brother Waco.
I like the way you setup your cameras in the video..

Other than my 7.62X39 I haven't shot cast or casted bullets for the last few years..
Fact is have shot very little the last two years due to back and joint problems, but things are getting better on that score..

Your thread here and vid. have shown myself and others that we don't don't need a 1:16/26" barreled custom wildcat chambered rifle to shoot @ 2500fps+..

As I don't own the 30 XCB mold I have a few questions before I consider ordering one..
1. How far off the lands are you with that bullet?
2. What is your COAL?
3. Does that bullet feed from both sides of the magazine?
4. Can you keep the bullet base in the neck of your .308?

That is all I can think of for now as you covered most all the bases with your reloading data..
Looking forward to you or your brother wacking a Muley buck this season as I am wondering how that bullet and alloy will act on game at high velocity..

TIA for your reply..

[Larry Gibson]

Heck, 2500+ fps out of any 308W rifle with a cast bullet is very easy........ the hard part is hitting something at any real distance........ it appears waco is succeeding.......anyone else?

[Hickok]

Waco, outstanding! Great video, and thanks for posting!

[Nrut]

Heck, 2500+ fps out of any 308W rifle with a cast bullet is very easy........ the hard part is hitting something at any real distance........ it appears waco is succeeding.......anyone else?
That goes without saying, that's why I didn't bring it up...[smilie=l:

[jmort]

LOL!!!!! I'm not going here again!!!! I know you were a big part of the design of the 30 xcb mold. You have told people for a LONG time that you can not get accurate (sub 2 MOA) loads with a fast 10 twist barrel at distance with high velocity.

500 yards. 2600+fps. Sub 2 MOA accuracy. Video proof. I don't care ONE BIT what you can do with 1:14-1:16 twist.
My point is you CAN do it with a 10 twist. No RPM threshold. At least I have not hit it yet.

Stellar groups and results Larry at 600 yards with your 1:16 twist custom rifles. I commend you. Well done Sir. I take nothing away from you.

I'm just showing everyone it can be done with a bone stock 10 twist at 2600+fps as well.

Happy shooting my friend.

Walter

Loved the video
Really enjoyed it
Hate the RPM non-sense

[megasupermagnum]

Whether or not there is a quantifiable "RPM threshold", surely there is a point at which a cast bullet cannot grip the rifling any more. I want to give higher velocity cast a try in rifles, for no other reason than to just find out what happens. I've got a handful of 30 caliber molds, and haven't tried really pushing any of them. If I were to buy a mold, why would the 30 XCB be a good choice, rather than some others? My own thinking with a 200 grain bullet, is that 2500 fps is REALLY pushing it with 308 winchester. Maybe higher pressure would be a better way to say it. With 200 grain you get a more manageable velocity range to work with , more bearing surface, and more thump down range. It should have a higher ballistic coefficient too. There's nothing wrong with the 170 grain at 1800 fps I've been shooting, but 200 grains at 2400 fps sounds like a lot of fun for shooting steel. I looked into paper patching, special alloys, etc. If I can't do it with a heat treated cast bullet, I loose interest. I've got a 308 Winchester 1:10" twist, may put a 308 1:12 twist barrel on my savage 110. My barrel has a generous throat. I have not measured it, but I can seat bullets out a long ways. Anyway, the bullet below is what I had in mind. It is calculated as 200 grains, and the gas check would probably be below the neck. What's so bad about the gas check below the neck?


230394

[waco]

waco

Perhaps you failed to notice my post was addressed to megasupermagnum. My post addressed the points/questions he raised. Whether or not you care "ONE BIT" or not is not relevant to my response to him. However, you certainly are entitled to your own opinion, just no need to denigrate someone else to make your point.

You are also still wrong. I have consistently told everyone for numerous years on this forum how to push the RPM Threshold up. The RPM Threshold is not a "limit" but can be moved up or down by using different components and bullet designs. On your previous 500 yard thread(s) I again explained how. The loads you used on those threads did, in fact, hit the RPM Threshold. That's why the load used then gave 4 - 5 moa. In this test you changed to a different, slower burning powder than previously used with a slower time/pressure curve which, just as I've consistently said to do, is a change of components. You also changed to an alloy closer to what has proven to be best at HV. Doing such it appears you have met with success with the load and components used in this thread. It indeed appears you have pushed the RPM Threshold up quite a bit in your 308W with 10" twist barrel, well done. In the previous post my only mention of you and your shooting in this thread was a compliment on how you are demonstrating how the RPM Threshold can be pushed up.

As to the information I posted to megasupermagnum, it applies to the bullet designs he mentioned, particularly the 311466 Loverin design in a 10" twist barrel and also in other twists. Those are not the NOE 30XCB you used. My explanation to him was to lend back ground information to the suggestions for his 200 gr bullet design and his questions regarding the 311466 Loverin design.

Question for you; do you think my milsurp F.M.A.P. M98 action with a Midway special $89.95 24" sporter contour Adams & Benet barrel in a sporter wood stock is the equal of your "bone stock" M700 heavy barrel rifle?

Depends. Is it a 1:10 twist? It's also a longer barrel than my 700
The alloy used is the same as last time.
And you should look at a burn rate chart. H414 is faster than IMR 4831.

[waco]

Great job to both you and your brother Waco.
I like the way you setup your cameras in the video..

Other than my 7.62X39 I haven't shot cast or casted bullets for the last few years..
Fact is have shot very little the last two years due to back and joint problems, but things are getting better on that score..

Your thread here and vid. have shown myself and others that we don't don't need a 1:16/26" barreled custom wildcat chambered rifle to shoot @ 2500fps+..

As I don't own the 30 XCB mold I have a few questions before I consider ordering one..
1. How far off the lands are you with that bullet?
2. What is your COAL?
3. Does that bullet feed from both sides of the magazine?
4. Can you keep the bullet base in the neck of your .308?

That is all I can think of for now as you covered most all the bases with your reloading data..
Looking forward to you or your brother wacking a Muley buck this season as I am wondering how that bullet and alloy will act on game at high velocity..

TIA for your reply..

1. bullet touching lands.
2. 2.750"
3. I single load the rifle
4. quite easily.

[Larry Gibson]

megasupermagnum

"....surely there is a point at which a cast bullet cannot grip the rifling any more."

The cast bullet not gripping the rifling is not the reason for the loss of accuracy. The RPM Threshold is when the centrifugal force acting upon the imbalances causes the bullet to begin an ever increasing helical spiral or to go off on a tangent to the intended line of flight. The bullets do not become unstable as they would if they "stripped in the rifling".

[swheeler]

Good job Waco, love watching your videos!

[megasupermagnum]

megasupermagnum

"....surely there is a point at which a cast bullet cannot grip the rifling any more."

The cast bullet not gripping the rifling is not the reason for the loss of accuracy. The RPM Threshold is when the centrifugal force acting upon the imbalances causes the bullet to begin an ever increasing helical spiral or to go off on a tangent to the intended line of flight. The bullets do not become unstable as they would if they "stripped in the rifling".

I've been reading your posts for months, if not years. You just confused me good. So why wouldn't a proper fitting bore rider work just as well for higher velocity use? This is assuming the nose is slightly engraving, bullet seated so the front band lightly jams in the rifling, and otherwise is a well cast and sized bullet.

[Larry Gibson]

Depends. Is it a 1:10 twist? It's also a longer barrel than my 700
The alloy used is the same as last time.
And you should look at a burn rate chart. H414 is faster than IMR 4831.

Yes the twist is 10", it's the same rifle you asked me to shoot at 500 yards in your previous threads. As per my question the barrel is a "Midway special $89.95 24" sporter contour Adams & Benet" which is 2" longer than your M700 barrel. Let me clarify the question as I was referencing your "bone stock" description of your rifle. Do you think/consider my put together rifle (by me, no custom work done....even has the milsurp trigger) using an Argentine made M98 action, the A & B barrel and an old sporter contour stock has any advantage over your "bone stock" non sporter M700 Remington? If you think it has an advantage what might that advantage be?

Yes H414 is listed in the charts as slightly faster burning than IMR4831 and it is probably most often with jacketed bullets. However with cast bullets I found in testing it in the .308W using the 30 XCB bullet and measuring the pressures H414 gives have a bit slower time/pressure curve than even IMR 4831 and H4831. That means with that cast bullet it is slower burning than the 4831s. I think that has to do with the ball vs stick shape of the powder and the different deterrents method of controlling the burn used on ball powder. The burn rate charts are guides, they are not written in stone.

[44Blam]

1. bullet touching lands.
2. 2.750"
3. I single load the rifle
4. quite easily.

Interesting. I was looking at NOE's site and they show "how to seat" this boolit and it has the GC in past the neck and a COL of 2.629". I have a different mold that is the 311-174-FN-AQ5 and I size to .311. I've only made dummy boolits so far to test the fit/function in my rifle and I found that if I seat it at a COL of 2.7" then about 0.07" of the boolit is past the neck and the boolit is about 0.005-0.01" from touching the lands - too close to measure with my calipers. But this is how NOE shows how to seat the 30 CXB...

These things are interesting... A little bit here and there makes things work or NOT work. I cannot wait to load and shoot my boolits.

Thanks again for the inspiration!

230401
http://noebulletmolds.com/NV/product_info.php?cPath=30_343&products_id=915

[waco]

44Blam. Glad I could help.

[waco]

Yes H414 is listed in the charts as slightly faster burning than IMR4831 and it is probably most often with jacketed bullets. However with cast bullets I found in testing it in the .308W using the 30 XCB bullet and measuring the pressures H414 gives have a bit slower time/pressure curve than even IMR 4831 and H4831

You really expect anyone to believe that a rifle can tell the difference between cast and jacketed Bullets to alter the burn rate of a given powder?
The only thing that would make any significance difference is if the bullet has any jump to the lands or is jammed. A cast bullet will have less drag going down the barrel than a jacketed bullet creating less pressure. Not sure where you come up with this?

[Larry Gibson]

waco

I never said the burning rate was "altered". What I said was the time/pressure curves are slower indicating the H414 powder was burning slower than the 4831s under the 30 XCB in the 308W cartridge. Had nothing to do with the rifle to "alter" the burn rate. I have measured the time/pressure curves....that's a fact.

And, yes, I do "expect" a lot of intelligent people who do not let their own personal feels alter their perspective to believe it. Here is just a couple of explanations (there are many more if you'd bother to look);

Why Powder Burn Rate Is Meaningless
By Randy Wakeman

Perhaps you have looked at various "Burn Rate Charts" and wondered what good they are. Well, you have good reason to wonder. Burn rate charts seldom agree. There is no specific meaning for "burn rate," so it shouldn't surprise us that the numbers don't agree. They mean nothing by themselves.

What amateurs call burn rate is not used by professional ballisticians to develop loads. The actual term closest to burn rate used in interior ballistics is "Relative Quickness."

Relative quickness is defined by "closed bomb tests," which quantify pressure rise in a sealed container. However, professional ballisticians do not use relative quickness for load development, either. A closed bomb relative quickness value does not translate into any type of value outside of that 'closed bomb' test. Powder performance varies widely by actual application. Relative quickness is one of several preliminary considerations when assessing a powder's suitability for a particular application by ballistics, but nothing more than that.

Relative quickness does not tell use the physical shape of a powder, its composition, or the types of coatings. It cannot tell us whether a powder is single-based, double based, or triple based. It does not tell us the heat of explosion, the progressive / degressive gas creation values, the ignition characteristics, and so forth. There is no way to translate a double-based powder performance into a single-based powder performance level with any accuracy. Even further, relative quickness does not define the erosiveness of a powder, the residue left by a powder, its ability to meter properly; and on it goes.

Energy content of nitrocellulose varies by manufacturer. It varies by the amount of nitrogen in the nitrocellulose. The more nitrogen, the more gas a powder can make. Once you have a specific type of nitrocellulose the energy content is further controlled by the addition of nitroglycerin, which is basically what constitutes a double-based powder. Now you have further considerations, as nitrocellulose and nitroglycerin do not behave the same way as temperature changes. The amount of nitro percentage varies by powder to powder, and with it its performance in a specific application.

All this combines to make burn rate charts something to ignore, or to view with very little importance placed on them. Professional ballisticians do not use them at all, simply because they have no particular meaning. Ping-Pong balls are nitrocellulose, but not many of us would bother cutting them up and attempting to use them in a firearm.

From Sierra’s Exterior Ballistics;

The following powders are listed by their approximate burning rate, from “fastest” to “slowest.” It must be clearly understood that burning rates are not linear. There may be several powders which have very nearly the “same” relative quickness listed together, with the next listed powder being significantly different. It should also be understood that the burning rate of any given powder can vary substantially when different cartridges are being compared. Smokeless propellants are organic compounds, and are subject to lot-to-lot variations that are unavoidable during the manufacturing process. As a result, it is quite possible for a “fast” lot of a “slower” burning powder to appear to be somewhat “faster” than a “slow” lot of what would normally be thought of as a faster burning propellant. This these listings are subject to change depending on the particular lots of powder involved and a host of other variables that become part of the equation.situation, in effect, would cause these two powders to switch positions in the following chart. Bear in mind then, that In the following chart, the column on the left lists the powder manufacturer along with their full designation for the powder in question.

[Nrut]

1. bullet touching lands.
2. 2.750"
3. I single load the rifle
4. quite easily.

Perfect..
Will be ordering one of these molds next month, Merry Christmas to me, lol..
And thanks for your reply..

[waco]

Perfect..
Will be ordering one of these molds next month, Merry Christmas to me, lol..
And thanks for your reply..

You are welcome.

[GregLaROCHE]

It's all theory, but if the limiting factor with the velocity of cast bullets is the alloys ability to hold rifling, I would think a bullet that is all bearing surface would hold the best. Maybe not. I now want to try some higher velocity bullets in my 308 Winchester 1:10" twist. I'll see how far the Lee 309-170-F will hold up. I was thinking a 200 grain bullet with just enough lube, all bearing surface, and a very short nose should be the best you will get. I've got one drawn up. I don't understand why the Loverin designs have the tiny drive bands, especially since so many recommend only filling half with lube. I would think 3 small lube grooves, with hefty driving bands would be a better way.

I can’t say from experience, because I haven’t tried it, but I have heard a lot about the difference between of boolits being hard and tough. I have had hard boolits come apart on me, so have tried to find out as much as it can on the subject. It’s been said that adding a little copper to the alloy makes it tougher and more able to stand up to the rifling with high speed boolits.

[Larry Gibson]

Interesting. I was looking at NOE's site and they show "how to seat" this boolit and it has the GC in past the neck and a COL of 2.629". I have a different mold that is the 311-174-FN-AQ5 and I size to .311. I've only made dummy boolits so far to test the fit/function in my rifle and I found that if I seat it at a COL of 2.7" then about 0.07" of the boolit is past the neck and the boolit is about 0.005-0.01" from touching the lands - too close to measure with my calipers. But this is how NOE shows how to seat the 30 CXB...

These things are interesting... A little bit here and there makes things work or NOT work. I cannot wait to load and shoot my boolits.

Thanks again for the inspiration!

230401
http://noebulletmolds.com/NV/product_info.php?cPath=30_343&products_id=915

Note that the top of the GC is still in/at the base of the case neck. That is the proper max seating depth. Injury to the bullet from gas cutting can occur causing leading and inaccuracy. Non-crimp on GCs could also be scraped off by the case neck base causing further problems. These problems don't always occur as a lot depends on the alloy used, powder used and the intensity of the load. In the NRA Cast Bullet Supplement there is an example of what can happen to the bullet if seated too deep into the case;

230411

The bullet on the left had the GC seated still in the neck. The bullet on the right was seated with the GC below the neck.

[44Blam]

Note that the top of the GC is still in/at the base of the case neck. That is the proper max seating depth. Injury to the bullet from gas cutting can occur causing leading and inaccuracy. Non-crimp on GCs could also be scraped off by the case neck base causing further problems. These problems don't always occur as a lot depends on the alloy used, powder used and the intensity of the load. In the NRA Cast Bullet Supplement there is an example of what can happen to the bullet if seated too deep into the case;

230411

The bullet on the left had the GC seated still in the neck. The bullet on the right was seated with the GC below the neck.

Looks like time to do some measuring and calculations as to were things actually are before I start shooting. I have some time to think about it anyway.

[megasupermagnum]

Something about that just seems fishy. If the bullet is a proper size, how would it be gas cut just because the gas check is blow the neck? Pressure would be very low at that point. i'm not aware of anyone using non-crimp gas checks anymore. I've been doing some research, and mtngun of Mountain Molds regularly shoots with gas check below the neck. He is shooting every bit as good as I'm seeing here, maybe better. Not to call anyone out, it just seems that people are finding success in completely different ways, which is so often the case in cast bullets.

[GregLaROCHE]

It seems to me, that if the GC is below the neck, the hot gases are going to be past the CC, that is supposed to seal them off, before the boolit begins to move. The GC may not even stay on.

[megasupermagnum]

It seems to me, that if the GC is below the neck, the hot gases are going to be past the CC, that is supposed to seal them off, before the boolit begins to move. The GC may not even stay on.

And yet, there is the rest of the bullet in the neck, no different than a plain base. I'm willing to bet pressure and velocity is extremely low while the bullet is still in the neck. Why wouldn't a crimped on gas check stay on?

[waco]

Almost any 300 blk Load is seated way below the neck.
Same on a 300 Savage.

[Larry Gibson]

It seems to me, that if the GC is below the neck, the hot gases are going to be past the CC, that is supposed to seal them off, before the boolit begins to move. The GC may not even stay on.

That is correct. The hot gases can erode the bullet in some instances such as the NRA CB Supplement photo demonstrate. As stated earlier how much occurs and whether it has any discernible effect on accuracy depends on many variables. Fact of the matter is I know of no CB bench rest shooters who seat GCs below the neck. If your rifle/load is 2-4 moa capable or you're shooting at close range then the adverse affect probably isn't discernible either, unless leading is a problem.

Crimp on GCs, if seated and crimped correctly, probably won't come off. It's the older non-crimp on slip fit GCs or the now home made thin non-crimp on GCs that pose the problem of coming off inside the case, particularly those that are a loose fit to begin with.

[Shopdog]

Nice job Waco! I regularly shoot high velocity out of tight twist barrels. My '06 CDL is a tackdriver @2800. Would love to shoot some steel at 500 but,don't have a convenient range.

[GregLaROCHE]

When a crimped on GC is referred to, it’s the type we normally buy or make and it is seated and crimped in place while the boolit is being sized. Right? I haven’t missed something where a GC is crimped on like factory crimp die crimps the case to the boolit?

[charlie b]

I believe Larry is referring specifically to the Hornady style gas checks rather than the 'straight side' gas checks that people can make at home. The difference is the 'edge' that Hornady puts on the gas check. When seated the GC is 'crimped' and makes a kind of groove in the heel of the bullet. As such it will not slide off the bullet without a bit of force.

The std GC's have straight sides so are dependent on sliding friction to stay on the bullet. They can be pulled off the bullet more easily. I would not seat one of those below the neck of any cartridge.

I've also used the XCB bullet in my .308, but, I powder coat and the Savage has a short throat. When seated and partially jammed into the rifling the gas check is well below the neck of the case. I have had some good groups with it when fired in the 1900fps range and even some great groups when fired at the 1100fps range. But, when the velocity goes up accuracy drops (also a 1:10 twist). I am still working with it to find out if I can push it any harder. I have been trying to recover some of the bullets so I could see what the bases and drive bands look like but have not had any luck so far.

[44Blam]

I love the left side camera.

[DonHowe]

I cannot shoot like that with jacketed. At 500 yards, the wind will get to me, even if the gun and load are capable. A 10 MPH wind will give over 2 ft of windage. Great shooting waco.
EVERYONE has to deal with the wind regardless of bullet material, velocity, etc. At high velocity the wind effect is less but still there,
even when in your face or at your back. In tricky wind put a 1400 fps boolit on target at 100/200 yes with wind in your face then fire one with wind at your back and watch your POI vertically.
If you set a flag every 100 yes to 500 yes, chances are they won't all read the same and air currents can vary between flags.
It' a fact of life.

[Cosmic_Charlie]

Very nice work there! I like the cheap seats though, sub moa @ 50 yds. with gc cast. Useful distance for pest control and fun. When I want to go long I shoot .223 ball ammo out of an AR.