Does Crimping 223 Cases Help with Cycling Action on AR-15?

[Tavor2017]

I loaded cast bullets with the minimum recommended load (Red Dot) from the Lyman Cast Bullet manual and the action on my Tavor X95 doesn't cycle. I am going to increase the powder charge. My quesiton is does crimping the cases help drive up pressure within the case such that it will increase the force acting on the bolt to help it cycle?

[Rattlesnake Charlie]

I loaded cast bullets with the minimum recommended load (Red Dot) from the Lyman Cast Bullet manual and the action on my Tavor X95 doesn't cycle. I am going to increase the powder charge. My quesiton is does crimping the cases help drive up pressure within the case such that it will increase the force acting on the bolt to help it cycle?

Not any noticeable degree. The "tightness" of the fit between bullet and case neck is more significant.

With "fast powders" such as Red Dot you may not reach a point where the gun will cycle. Fast powders may reach peak pressure and then begin to drop off before the bullet passes the gas port. Do not exceed recommended powder charges. You may need to switch to a "slower" powder that maintains sufficient port pressure to cycle the action.

There ain't no such thing as a free lunch.

[Tavor2017]

Thank you for the reply. I am going to to some reloading and then shooting this weekend. I will reload with a charge near the maximum recommended Red Dot load but also look at my Lyman book for a slower burn powder with a defined load for my 223 lead bullets and try that powder as well. My Lee crimp die arrived today so I will see if that helps as well. It is a pain to pull the bolt back manually after each shot. Thanks again!

[country gent]

The AR is gas operated you need a certain volume of gas thru the port to the bolt to cycle it reliably. Work up the load a little and see if it improves. A crimp may improve burn some. In the AR you may need to go to a rifle type powder to get functioning. What velocity are you looking for? Is the rifle unlocking and partially functioning? Port pressure and volume is whats needed to function the rifle. You might try a light crimp to improve burn

[Tavor2017]

I am loading powder coated lead bullets and I am trying to prevent leading and don't want to use gas checks so I am trying to keep the velocity as low as I am able to. The accuracy was decent at 50 yards with the Red Dot and there was no leading. The velocity was approximately 1700 fps. I didn't notice how much the bolt moved when I was shooting but it wasn't enough to partially eject spent cases and cause jams. I felt like I was shooting a bolt action rifle. I am looking to shoot cheaply and for longer distance shooting will likely go back to jacketed bullets with rifle powder. I learned the hard way, before I found this forum or the Lyman casting handbook, not to use the same powder and loads on lead bullets as used for jacketed bullets. The accuracy was terrible. Even at 25 yards I think some of my shots missed the paper entirely and the inside of my flash suppressor looked like it had been chrome plated it had so much lead build up. I will try an increased charge of Red Dot and a light crimp before trying another powder. Now I know to try a slower powder if I still have trouble. Thanks for the help!

[robert12345]

Shooting cast bullets in an AR-15 is rather tantamount to turning your "AR" into a bolt action 22 Hornet.
.
If you want accuracy with cast bullets, ..you must keep your velocity down, ...to keep velocity down, ...you reduce the powder charge,..a reduced powder charge generates not enough gas to cycle the action,

and, you end up with a bolt action AR-15.

[JonB_in_Glencoe]

I use H4895, there is a narrow window where the action begins to reliably cycle, but then much faster and you start to lose accuracy.
With my boolits it was around 17 to 18 gr.

FYI, I use the Lee FCD, and put a pretty solid crimp on it.

[Dieselhorses]

I know this thread got a little dust but.... did a few test with the Lee C225-55-RF powder coated-no checks. Only 25 yards but using 1X red dot off hand. I mainly wanted a load accurate enough for close quarters. Soon as other AR is built will be for longer ranges. 19 gn H335 cycles every time. COAL just a smidgen away from lands. 10 shots first pic, 20 in second.