300 BLK reloads and new build

[belizejet]

The bottom one is my first build. It's in 300 BLK. It's almost done, however my reloads are not chambering. The factory ammo cycles though. I've taken a micrometer to the case dimensions and they are at the same measurements as the factory Remington ammo. I guess I should really say that they won't eject. They chamber but when I try and charge it for the next one they get stuck. Any hints or tips. The only difference is the profile of the projectiles are different. I have not gotten to the range yet with it.

spikes lower
FN 1/8 16" barrel
RRA lower parts kit and national match trigger
samson evolution rail

Just a few of my splurges.

[Hoser]

The bottom one is my first build. It's in 300 BLK. It's almost done, however my reloads are not chambering. The factory ammo cycles though. I've taken a micrometer to the case dimensions and they are at the same measurements as the factory Remington ammo. I guess I should really say that they won't eject. They chamber but when I try and charge it for the next one they get stuck. Any hints or tips. The only difference is the profile of the projectiles are different. I have not gotten to the range yet with it.

spikes lower
FN 1/8 16" barrel
RRA lower parts kit and national match trigger
samson evolution rail

Just a few of my splurges.

What powder/bullet/velocity/ect?

[KS63]

Info on the projectiles.

[AKA-Spook]

The bottom one is my first build. It's in 300 BLK. It's almost done, however my reloads are not chambering. The factory ammo cycles though. I've taken a micrometer to the case dimensions and they are at the same measurements as the factory Remington ammo. I guess I should really say that they won't eject. They chamber but when I try and charge it for the next one they get stuck. Any hints or tips. The only difference is the profile of the projectiles are different. I have not gotten to the range yet with it.

spikes lower
FN 1/8 16" barrel
RRA lower parts kit and national match trigger
samson evolution rail

Just a few of my splurges.

....seat a bullet deeper in .010 increments up to .050 and see if that frees them up. If you've gone past .030 I'd start to worry. Remember, as case volume decreases , pressure increases in case you're loading up to the edge.

[belizejet]

"....seat a bullet deeper in .010 increments up to .050 and see if that frees them up. If you've gone past .030 I'd start to worry. Remember, as case volume decreases , pressure increases in case you're loading up to the edge."

Thats what I was going to try. I've loaded them a little light with 18.9 grn H110. I've loaded nosler ballistic tip 125 grain and some 110 grn Amax. Don't have exact recipe with me. I noticed the shape of the bullet is causing it to scrape in the chamber. It doesn't taper down as fast as the factory ammo. If I seat it a little deeper I might avoid that.

[KS63]

Who's factory ammo?

[belizejet]

Remington

[KS63]

I've used the Nosler 125gr BT projectiles with zero problems. Nosler does have reloading data on the Blackout. I reload COAL are a little longer than what they tested at. No problems. Try using a Shapie and mark the bullet ogive and the case. Drop the cartridge in the chamber by hand and close the bolt. The marks on the bullet and brass may give you an idea of where a problem exists.

[20X11]

What is the trim length of your cases?

[legaleagle]

Had a similar problem with colt defender - 45 acp. Factory rounds worked perfectly, however reloaded with full length resize would not chamber all the way. When inserted by hand in barrel after dissaembly, it was noticed that some would sit flush with barrel hood, others would be about 3/32 from chambering. I noticed profile of bullets was slightly different and at recommended OAL I would get a ring on bullet after spinning it in chamber because it was resting against the rifling - bullet was fatter toward tip than other factory rounds. I sat bullets .020 deeper and reduced powder charge due to smaller internal volumes and increased pressures. This helped problem, but did not solve. Back to square one, I went through entire loading procedure and noticed that my crimp dies was not crimping as I thought. I reset and ran rounds through that were not chambering and whoala, everything fixed. Then I loaded to recommended OAL and crimped, with no problem in loading. I understand the 45acp head spaces off the case, not the bottle neck shoulder. However, without the crimp at .002, there was just enough flare on the case to make things tight. Not sure if this will help you, but thought I would share experience. You may also double check your case length. If you trim prior to resizing, the resizing will add some length to the case as the o.d. diminishes the length increases - I have seen as much as .006 on rifle cases.