45 ACP reloading- Red dot, Magnum primers, and MBC 200 gr RNFP

[mgrs]

All- long time lurker here and have been very impressed with the information and attitude on this forum. I hate for my first post to be a "what am I screwing up?" post, but I have started loading .45 ACP cast lead due to high ammo prices.The fastest turnaround I could find was from Missouri Bullets.

I have been loading bottleneck rifle for a long time but just started straight wall pistol due to ammunition prices.

I've had some strange problems with the following:

200gr MBC RNFP, CCI 350 primers, CCI Brass. OAL 1.190-1.195.

Loaded on an xl650 with lee dies, belling just enough to seat without shaving lead and taper crimping just enough to remove the bell. Case mouths mike at .472-.473.

Issues:

1) 15-20% of the rounds loaded to this OAL will not "drop check." Although they mike to the same OAL, the bullet ogive engages the throat early. On the loaded ammunition that will not chamber, I tried re-seating by .05 increments until it will chamber. Most of the 'rejects' have to be seated to 1.140 or deeper before the bullets will stop jamming in the throat before fully chambering. Some have to go all the way down to 1.120. This seems to be a large spread and they are visibly much deeper. Some of it might be due to leftover casting flash, but I'd hate to have to remove the flash from each bullet individually before loading.

2) Velocities seem high for charge weight compared to book data. (this is for the 200gr RNFP @ 1.195, all loads measured for OAL and drop checked OK)

Red dot 4.3gr starting load: 852 AVG, 32es, 173pf (4.4 gr gives me the same results, anything above 4.5 starts to flatten primers)

Power Pistol 6.6gr starting load: 952 AVG- flattened primers, heavy recoil

It seems like a very narrow window between a low major load and flat primers. Could it be the magnum primers spiking pressure?

On the plus side, I am not getting any leading from the Red Dot loads.

Long story, I know. I'm going to drop to 4.2 red dot with 1.185-1.190 for the next string.

Thanks in advance for any advice!

[tires2burn]

I have no info on loading 45 ACP with red dot. Your OAL seems to short. I run titegroup at5gr OAL 1.250. Mag primers ????

[mgrs]

I have no info on loading 45 ACP with red dot. Your OAL seems to short. I run titegroup at5gr OAL 1.250. Mag primers ????

I thought the OAL seemed short also, however even at 1.20, most of the loaded rounds will not chamber without force due to the ogive hitting the throat too early. They would be dangerous to fire in this condition.

Yes, I am using mag primers. I get a very clean burn at all charge weights, but that may be due to the pressure.

Thanks!

[gordonm1]

I did not see the gun mentioned. You can try a 0.469" taper crimp on my recommendation or just try more crimp.

My XD45 requires the shortest OAL of the 45 ACP guns I have. 1.200" at 0.469 crimp works for it and I shot about six pounds of red dot mostly with the MBC 200 RNFP advertised as a good bullet for the XD45.

Loaded so short I did not go over old published data and enjoyed it. A case gauge would help tell if your rounds are an issue or your gun is the problem.

[mgrs]

Thanks gordonm1. I did try both taper crimping to .469 and then running the loaded round through an fcd sizing ring. The cases were fine and these extra steps were not needed. Did not fix the problem. I tried forcing some of the rejects into the chamber (bare barrel) and they came out with lead shaved off the ogive where it met the throat. They were still shaving lead even when seated to 1.180.

Gun is a Springer range officer with factory barrel. It sounds like I may have a short chamber or a bad batch of bullets, or both.

[Steve RA]

I'd vote for the short chamber. I use the same bullets @ 1.249 and have no problem. Try one of your loaded cartridges in another .45 and see how that works.

[mgrs]

I'd vote for the short chamber. I use the same bullets @ 1.249 and have no problem. Try one of your loaded cartridges in another .45 and see how that works.

Steve, I can get about 1 in 10 or less to chamber at that OAL. I'll check some of the 'rejects' in two other brand 1911s tomorrow.

I've had no problems with multiple brands of factory jacketed ammunition, but it is made to fit a wide variety of chamber dimensions.

[Shooting Coach]

I load this bullet to 1.210" in 2013 production Springer 1911 RO. No issues.

[mgrs]

Cracked the code.

My chamber headspaces OK, but there is "no" throat. The rifling is just right there with no transition. I tried my rejects in a friend's kimber, and they chambered. He gave me some of the jacketed reloads he shoots, and none would even come close to chambering in my pistol.

Even with the 200 gr rnfp @ 1.190", I am still encountering rounds that hopelessly lock the gun up.

Are they any gunsmiths commonly used by folks here to fix this problem?

Thanks

[Steve RA]

Throating reamer will do it.

[mgrs]

Update:

Before buying a reamer or paying to have it done, I lapped the throat and then switched to RMR 230gr hardcast. No more problems. There is a 'step' between the bearing surface and ogive instead of the direct taper on the MBC 200gr RNFP.

They also appear to be a much higher quality bullet- no thick molding flash or uneven molding like the MBC I was using. The bullet lube is also on the bullets, instead of in a pile at the bottom of the box....