450 Bushmaster AR HELP !!

[Mr Humble]

This is my second one. Bushmaster upper on a Remington (Bushmaster) lower. 1.5-6 Leupold. Shoots Hornady factory (jacketed) so good it's scary. 3 frequently a clover leaf @100.

No shortage of .452 cast boolits. Have a Lee 300 gr GC semi wadcutter that is deadly in my 1926 Colt New Service Match Target. So I dug out my stash of Bushmaster loading data. In-terp-polated and tried H110 and 4227. Not enough H110 to fully cycle, 4227 worked but there are feeding issues.

Neither shot what could be called "groups".

This was my result with H110 .... not too bad you say ..... it was shot a FIFTY FEET ! (12 shots)

At 50 yards is was a joke but the semi wadcutters are cutting clean holes, no tipping.

Twist is 1 in 16 and some claim its a gain twist.

Thoughts ? Suggestions ? Thanks !

[Yodogsandman]

Work out your feed issues and it will probably come around. Check seating depths and crimp amounts.

[Mr Humble]

450 BM uses a tapered crimp and is set correctly.

Gonna seat em' in farther as semi wadcutters never are great semi auto feeders. Also gonna try some lighter/shorter boolits as Hornady slugs are quite short. 200 gr truncated cone .452s might be better.

[rockrat]

I use Lil Gun in mine with the Lee boolit sized .454". 2" and less @100.

[Mr Humble]

Today I tried 200 gr truncated cone wadcutters w/37 gr of 4427 and CCI SR magnums.
Out of 10, I had 4 bloopers and six all over the place. Have to recheck my dies as the taper crimp on this cartridge is very critical.

[Mr Humble]

I use Lil Gun in mine with the Lee boolit sized .454". 2" and less @100.

Charge ? primer ? which Lee ? OAL ? taper crimp diameter @ mouth ? Thanks

[Whiterabbit]

I've shot a 460 S&W with a 1 in 16 twist with what seems like every cast bullet under the sun minus a 200 grain GC (call me if you have some) with H110.

Anyways, I have had similar results to you, in similar conditions. I suggest you up the bullet weight to over 400. Try some 45/70 bullets in the 400-540 grain weight. 400-450 with gas check. Above 450, no need. Still with H110, even up to and above 540 grains. Make sure the bullet selection has LOTS of driving band. Lots, and lots, and lots.

I think you'll fine something accurate much more easy.

And if not, my second suggestion is to reset with the 300 grain bullet that feeds, and try a new powder. H4198 or similar. something slightly slower than H110, a fast rifle powder. Something on the very fast side for 223, even just too fast. That range.

[Mr Humble]

Thanks. I have the 300 gr Lee 452 300 RF GC that I'll try with 4198. 450 Bm loading data is scant but the 460 S&W data is close. As loads for 4227, Lil Gun and H110 are available for both, some caution interpolation should provide a start for 4198.

I also have tapered crimp diameter issues (very impt in BM) to correct. First I have to blast out all that unburned 4227 out of the gun.

[Mr Humble]

Got the crimp issue fixed, no missfires.

Tried the 300 Lee GC again with powder coating.

Tried 4227 again and 4198.

Groups @50 still 5" with no evidence of tipping.

The same bullet shoots very well in both 45 Colt and 460 S&W.

I'm gobsmacked !

[Yodogsandman]

Are you using gas checks?

Have you fired a round and then checked for nose damage on the next round by hand ejecting it?

Try different seating depths. Roll loaded rounds on a flat surface to see if they're seating straight.

Powder coated boolits have consistency problems due to the uneven surface coating. Powder coated boolits are not as accurate as lubed ones. Any decent lube should work well.

[Mr Humble]

are you using gas checks? Yes

have you fired a round and then checked for nose damage on the next round by hand ejecting it? All are single loaded

try different seating depths. Roll loaded rounds on a flat surface to see if they're seating straight. Seating depth is pretty much fixed to get feeding. They are straight. The hornady dies are a 4 die set .... #4 aligns and taper crimps

powder coated boolits have consistency problems due to the uneven surface coating. Powder coated boolits are not as accurate as lubed ones. Any decent lube should work well.

found some groups i shot in my first 450. Used lil gun and lubed boolits. About 2" @50 yards.

Where does "powder coated not as accurate" come from ?
Have there been side x side tests published here ?

Thanks.

[Yodogsandman]

"powder coated not as accurate"

You can quote me for that statement, my personal testing proves it in my rifles. I have not shot PC in any pistol, I lube those with BLL.

Have there been side x side tests published here ?

Not that I've seen. Most using PC in rifles say that they get great accuracy but, don't post the results. Look in the PC sub forum for any posted results.

http://castboolits.gunloads.com/show...fps-or-greater

[Whiterabbit]

Got the crimp issue fixed, no missfires.

Tried the 300 Lee GC again with powder coating.

Tried 4227 again and 4198.

Groups @50 still 5" with no evidence of tipping.

The same bullet shoots very well in both 45 Colt and 460 S&W.

I'm gobsmacked !

Get someone to send you some 405 grain 45/70 bullets, and put then through the .452 sizer. Give them 32 grains of H4198 and tell me how that works for you.

Note: I have no idea what the pressure is for that load, but it's WELL under the 65ksi ceiling for 460 S&W so I'm making an educated guess that it's near 50ksi for an AR-15, but I have no idea, and it's not my cheek on the thing when the trigger is pulled. I can also say that the load can tolerate going way down in powder, 29, 28 grains, so you can work up if you want. But should find a node in the 31.4-32 grain area.

[Mr Humble]

Have some 330 RN 45-70 boolits, sized em' to .452. Trying Lil Gun as it was the best with my previous 450BM with the 300 gr .452 Lee GC boolit.

If that fails, I'll try 4198 again.

Thanks !

[Whiterabbit]

OK, but keep in mind my #1 purpose was to get you trying heavier (longer) bullets, particularly if they are plain base. My personal advice wouldn't change if you reported no success with the 330's.

[Gtek]

Bushmaster factory upper, 1-16" ?

[jcren]

Check with Smoke4320. He sells pc and has posted many targets showing it can be done. I believe one of his rifles is a big bore ar, but details escape me.

[Mr Humble]

Yes it's a Bushmaster upper on a Remington (Bushmaster) R15 lower.

[rockrat]

Sorry, Lee 300gr mould for the long colt. rifle gas checks. .454"dia. Rem 7 1/2 primer. 32gr Lil Gun. (works in MY gun, the way I load it--use at your own risk). I taper crimp using a 284 win. sizing die.

[Mr Humble]

RR, thanks, there is only one Lee mold that is a .452 300 gr GC. (45colt/454casull), that's the one I have. I have been PCing it and running it thru a .452 Lee die. I'll try it w/o sizing which should put at @.454.

In the past when using it with SPG, no leading but 4-5" groups @50.

First I have to try the resized 45-70 boolist suggested by WhiteRabbit.

I have the Hornady 4 die 450BM set that works perfectly when you taper crimp ONLY and not less than .474.