Looking for advice 9mm carbine bullet weight what is best?

[tayous1]

I acquired a AR-9 with a 16" barrel in a trade and I have been looking for information on what is the best weight bullet for this weapon? I will also say that I'm looking to make it a pistol with a 12 inch barrel as most of the load data I saw put the 12 inch barrel giving higher FPS then 16".

I'd like advice for both of I could. I have tried to search this information and came up with three gun writers who praised 115 gr, 124gr and 147gr for a carbine.

Yet I was told by other loaders to stay away from the 115gr JHP as they fall apart. Other say the 147gr is for short barrel pistol and not as practical and useful with a carbine.

I only loaded 9mm back in 2014 and it was 500 rounds for a friend of 115gr lead. So I know nothing about this so any advice would help thanks!

[G W Wade]

My friends and I seem to think heavy bullets are performing better in our assorted PCC GW

[ofitg]

I could be mistaken, but if your weapon was originally manufactured (and is on the books) as a rifle, I believe you would be violating federal law by putting a pistol-length barrel on it.... unless you process the appropriate paperwork and get approval from BATFE.

[BNE]

I am using 150 grain and 147 grain bullets and am very happy with them. The "AR-9" is very fun gun to have.

[tayous1]

I could be mistaken, but if your weapon was originally manufactured (and is on the books) as a rifle, I believe you would be violating federal law by putting a pistol-length barrel on it.... unless you process the appropriate paperwork and get approval from BATFE.

It was a build lower so it was registered as other when my FFL received it the weapon was taken apart no stock on the lower also no upper so it was registered again as other! Have it taken care of. At no point did I say it was a rifle did I?

I asked about bullets not about your feeling about a situation you know nothing about! Sorry if that's rude but let's keep on topic.

[tayous1]

I am using 150 grain and 147 grain bullets and am very happy with them. The "AR-9" is very fun gun to have.

Have you use any JHP in that weight range?

[gpidaho]

tayous1 My 9mm AR is 11" barrel and 124gr and 135gr. cast bullets work well for me. Gp

[JimB..]

I mostly run 147 gr JHP (Hornady xtp) or or 158 gr fmj. Also run some powdercoated swc in the same weights. Fast powder (titegroup mostly) with a 5.5” barrel suppressed.

If you do not plan to suppress then you just have to decide if you’re in the heavy/slow or light/fast crowd. It is more economical to shoot 115gr, but I like the idea of heavy/slow in everything but my sig 365 where I’m toying with 65gr bullets at high velocity.

I would ignore anyone saying that a 115gr fmj is going to come apart at any velocity you might attain. Not saying it isn’t possible, but I’ve never seen it. If it happens you’ll know right away from a paper target, so no need to listen to him or me.

[tayous1]

tayous1 My 9mm AR is 11" barrel and 124gr and 135gr. cast bullets work well for me. Gp

Have you used JHP? I want to do cast but want to make sure I buy the right cast even though an extra 147gr would not be bad!

[Bigslug]

I've chrono'd Winchester's 147 grain duty loads and they picked up an average of EXACTLY 100 fps out of a 16" Ruger over a 4.5" Glock 17 - 1008 to 1108.

The load I ended up with for cast was a 135 grainer WFN at 1030 fps from the Glock. If I chrono'd it in the carbine, I disremember the numbers, but for sake of keeping it simple, let's just call it 1130 - - still subsonic. I like that weight for cast simply because while a hollowpoint might need the extra weight to penetrate well after expanding, a non-expanding round does not (it gave me nine - almost ten - one-gallon milk jugs out of the Glock). I'll grant that my hypothetical 22fps carbine boost over the 147 is not a major trajectory flattener, given the sub-100 yard primary use of such things, it doesn't hurt any.

[Tokarev]

Ran 125gr in a 18.5" bbl from average to hot and printed good groups with iron sights. 2" at 10 yards standing with rapid fire, 1" from a rest.

[1006]

You shouldn’t have any problems with the lighter bullets (115) as long as they are Jacketed. A carbine barrel will add enough velocity to some loads to cause a soft lead swagged bullet to come apart.

I have found a very nice load in a 16inch AR9 to be 3.5 Red Dot, and a 135 grain cast powder coated bullet. The barrel has a 1 in 10 twist.

[Handloader109]

115gr coming apart out of a 9mm? at a little over 1000fps? ain't never gonna happen. I would discount anything those guys ever say. Now 2000fps? maybe, but you won't get within 800fps to that speed. I've shot 115 up to 152 out of my carbines and 7 to 8 inch pistols with good result. pick one and just use it.

Sent from my SM-G892A using Tapatalk

[Tokarev]

A carbine barrel will add enough velocity to some loads to cause a soft lead swagged bullet to come apart.

That did not seem to happen in my Mosin carbine that had a mighty long barrel compared to 9mm carbines. I shot a 90gr 314 bullet with no issues but poor accuracy that all Mosin carbines with pistol bullets are infamous for.

[1006]

The Berry Bullets 125 and 115 grain 9mm has a recommended max velocity of 1250fps. They will hold together better in a 1/16 twist barrel better than in a 1/10 twist. Other soft lead bullets have the same issues if accelerated beyond a light load’s velocity.

My personal experiences of bullet failure have been with faster twist barrels (1/10twist 9mm or 40) and softer bullets.

My 9mm carbine has a 1/10 twist barrel and sends the 135 grain, hard cast bullet at 1390fps. The same load only makes 1132fps from a Sig226. I am pretty sure the 125 and 115 Berry Bullets would be pushed too fast with a max load in the carbine. It is a valid concern.

I have seen the soft bullets come apart in an HK USP 40S&W. It took me a while to figure out why the target kept showing three or more small holes rather than one 40 caliber hole.

[1006]

That did not seem to happen in my Mosin carbine that had a mighty long barrel compared to 9mm carbines. I shot a 90gr 314 bullet with no issues but poor accuracy that all Mosin carbines with pistol bullets are infamous for.

I am wondering what the velocity was, and if your bullets may have been starting to fail as the lack of accuracy might indicate.

[Tokarev]

No, the bullets have not been "starting to fail". Where did you get that idea?

[1006]

I was thinking maybe they were starting to fail, reducing accuracy, if the velocity was too high.

My Sig226 has to be loaded on the light side to get any accuracy from softer lead bullets, it is extremely accurate with FMJ or hard cast bullets.

I have run into this issue with faster twist rate barrels. Most recently, while learning to load for the 300 Blackout with Berry’s 150 grain bullet, I observed the bullets became wildly inaccurate if fired at over 1900fps. Some completely missed a poster sized target at 100yards. They may have come apart-I never found any evidence of a hit. Once I slowed them down to approximately 1850fps, the accuracy was better the 1 moa.

[Tokarev]

Mosin carbines shoot cast and FMJ pistol bullets equally poorly at any velocity. This has nothing to do with your overspeed issues.

[winelover]

FYI, Berry's Bullets offers 9mm bullets in Triple Plate for the faster velocities of carbines.

Winelover