Newby to 450 Bushy/Pistol

[Andrew065]

Hi Fellow 450 BM shooter! Frst post as I recently acquired a 450 BM pistol ( AR, 10.5 ").

I Really enjoy shooting the shorty Thumper but have a short barreled/pistol question.

Load Data:

Lee Dies, Lil Gun powder and 250 XTP ( yeah I know, not rated for High Velocity) and 300 XTPMags in Starline cases with CCI 41 primers.

I seem to have unburned powder in the bore/chamber with the 250s, they run around 1650 with 31 grn of Lil Gun crimped at 2.085". Cases are somewhat sooty at this charge, but less so than at the starting load of 28 grn. Is this common with short bbl'd 450s? I don't want to run the charge up as these bullets are again, not the right ones, once these are gone, I will use only HV rated bullets. With similar but rated bullets, would increasing the charge and thus pressure/heat help burn more of the powder? ( I know I will eject some unburned powder simply due to the short bbl).

300s seem to really shine- same charge and COAL, they run at 1780 fps ( n=3, so not definitive) and the cases are much cleaner.

I had some CCI 400 SR primers left over, so I loaded a few rounds with them. Definite delay in ignition with these guys. Is that common? Didn't think LilGun would be hard to light.

Accuracy at 50 yds is okay, just okay ( Bear Creek barrel, but I have good success with other Bear Creek products to date), using a 3 MOA red dot. It will kill a deer.

[plant_one]

switch to a bullet that can handle 450 bm pressures and then warm up those lil gun charges.

31 grains is relatively low charge for LG - the magic sauce for the 450 seems to be around 38 grains with a magnum primer. I get nearly identical results with the cci 450, or the 7½... and even the 400 worked well for me. but again that was with 'normal' powder charges at the top end of the load data range (38 and up)

the delayed ignition i would suspect with the standard primer has as much to do with the reduced powder charge as it does the primer choice. or at least the combination of the two issues anyway.

[Andrew065]

Okay, I get it that the 250xtp is not a bullet to use.

Regarding the charges you suggest, for a 250 ftx or the 240 xtp mag, or similar class, right?

I am just below the max charge listed for the 300, and I understand the Bushmaster bolt/ extension in the AR are said to be less robust , is where I am now where it should stop(32 grn Lgun)? Just wondering.

[Bmt85]

Hodgdon lists the start load for Lilgun, using a 250 FTX, at 35gr. That should be close enough to start the 240gr XTP Mag, too.
Don't know, what Hornady or Lyman AR manual have listed, don't have the books near me.

When doing load work up, you can surpass book loads in an AR, but you have to watch EVERYTHING! Really check for case head growth, and for any markings or imprints to the brass from the bolt/ejector. The bolt is a weak link for an AR in 450B, hence why if you see imprinting, stop there. That means your inducing far too much force on the already weaker bolt.

[Andrew065]

Thanks.

I won't plan on going past the max charges- been there done that with lots of other stuff made for pressure. Besides, how much more should I expect from a 10.5" pistol? I think the efficiency breaks even at some point and the rest is just going to be flash blast and wasted/unburnt powder. ( However, I am all for added carbon to he environment, if just to make liberals heads explode....)

Being a pistol, I plan on using pistol type LER sights ( currently a Bushnell TR25 red dot) but it is really neat having a brace to seems to be very useful... I expect it to be useful out to 100yds or so for local deer hunting and bear deterrent when in proper country.

[Bmt85]

Yeah, you probably won't gain a whole lot going past max loads in a 10.5" pistol. I would, however, go past book loads if it means I get a better case-to-chamber seal and better accuracy. Some loads I have worked up would still have carbon down the case until I hit max, or almost max, then I hit an accuracy node just above that.

With the 10.5" barrel, you should really chronograph your loads, and find out the minimum velocity required for expansion of your bullets. I know the 275gr TSX has a minimum velocity of about 1200fps, and you can run it as fast as a 250gr FTX. Plus, it's a better bullet than the FTX, IMO. The 250gr Maker has a max velocity of about 2000fps, I believe. Don't know the minimum, but I would guess it's close to the TSX. The 275gr Maker offered from Black butterfly, looks to be the same. So even with a 10.5" barrel you should be able to get well past 100yds, if you needed to.

[plant_one]

hornady's 10th lists the following for 450 bushmaster charges with lil gun

250 ftx @ 2.225"
lil gun, WSR Primer
min: 25.2
max: 37.9


240 xtp mag @ 2.060"
Lil Gun, WSR primer
min: 25.7
Max: 38.3

you shouldnt need to start as low as 25.x grain min charges... i used to start at least 32 grains and move up from there.

additionally Most of us are using rem 7.5 or cci 450 magnum primers with lil gun for almost all of our 450 loads.


with the 300gr xtp mags you're about right on the mark stopping at 32 gr of LG... thats a STOUT load with some hefty recoil, and just a RCH under book max for that bullet.



from the forum here if you do some digging you'll find that the 225 FTX @ 2.120"-2.125" (put the case mouth right in the cannelure) over 38 gr of lil gun is a pet load for many of us. start around 32 grains and work up.


HTH

[Bmt85]

hornady's 10th lists the following for 450 bushmaster charges with lil gun

250 ftx @ 2.225"
lil gun, WSR Primer
min: 25.2
max: 37.9


240 xtp mag @ 2.060"
Lil Gun, WSR primer
min: 25.7
Max: 38.3

you shouldnt need to start as low as 25.x grain min charges... i used to start at least 32 grains and move up from there.

additionally Most of us are using rem 7.5 or cci 450 magnum primers with lil gun for almost all of our 450 loads.


with the 300gr xtp mags you're about right on the mark stopping at 32 gr of LG... thats a STOUT load with some hefty recoil, and just a RCH under book max for that bullet.



from the forum here if you do some digging you'll find that the 225 FTX @ 2.120"-2.125" (put the case mouth right in the cannelure) over 38 gr of lil gun is a pet load for many of us. start around 32 grains and work up.


HTH

Hodgdon lists a start load for the 225gr and Lilgun at 38gr. I personally got slight hang fires in a couple of my rifles when going under 35gr. Personally I would start around 35gr and go up slowly from there. You should find an accuracy node somewhere between 35 and 40gr.

[Andrew065]

Thanks fellows,

I will likely stay with the 300XTP Mag, it clocked a decent 1785 AV, 23 SD and 47 ES. That puts it right about where I thought it might max out at. 32 grn LilGun, CCI41 ( = to 450) because I have many, the 7.5s go into the Service rifle loads.

Stuck a telescope on it yesterday to chrono, at 50 yds I held about a MOA from a supported bench , for my bear country/break CMU walls gun, that'll do. The Irons, I zeroed them 2 " high at 50, they were about an inch high at 100 and the same low at 150.

What a fun gun. I really like the brace too. ( I learned to not do nose-to-charging-handle like I do for position shooting the AR Service rifle- straightened that crooked tooth it did- as a lefty the FA button kissed my upper lip...)

I am using chamber tactical followers in C-Products 30 round GI mags, they'll hold 11 with a bit left to allow locking the mag on a closed bolt. Squeezed the lips a bit to keep the top f=round from titling and interfering with the bolt catch. Can I trim some leg off to gain a round or so? Reliability?

No failures with the 300s, all the 250FTXs loaded are gone. Everyone with a cci 400 had that noticeable delay. No more.

I anneal my 223 case necks for consistent neck tension and was wondering what the thoughts are ref annealing 450 BM cases? Never annealed any normal pistol cases before, but is this one any different? Would an occasional anneal help case life and or neck tension/chamber seal? Probably not.

Blessings

Andrew
Major, US Army (ret)

[Bmt85]

I've played with modifying a couple 223 mags. IMHO, if you can get 10-11rds in one, and keep it reliable, I would stop there. I have an aluminum GI mag that I modified the follower on, it fits 11rds and works just fine. I have a C-products 223 that I heavily modified the follower and clipped the mag spring a little. I got it fit 13rds, and it works, but honestly, it's sketchy. The follower had to be modified so much there isn't a lot left, and it can nose dive pretty bad. Not that it did, but it's capable. Mainly, to fit more than 10-11rds, the follower has to be able to tilt like crazy in the mag, which is not good.

As far as annealing, I haven't and probably won't. I know Hoot tried it, and I don't think he really saw any difference. Maybe if you were having issues with the case mouth splitting, then sure.