.450 Bushmaster - AR-15 cast bullet loadings.

I am looking to do some reloading for a .450 bushmaster AR-15. I have nit loaded for this caliber before and i am finding sparse data. Does anyone already reload cast bullets for this caliber? I do have some load data via the AR Reloading handbook by Lyman. I have a mold dropping 270 gn bullets gas checked. Can anyone offer me any tips they learned reloading for this caliber? Currently i am sizing my bullets to .453. I have loaded some ammo using the 325 gn load data. When these rounds are chambered they stick in the barrel and I need to use a rod to get them out. Does that indicate the bullets are to large and should be sized down to .452? I always thought you wanted to be .001 gn larger lead bullet to ensure positive contact with yhe rifling am I wrong in that belief? In case anyone is wondering i used a 1 to 1 mixure of lead and lynotype that typically is aroung 20 or 22 bn hardness. These bullets are gas checked as well.

Any and all input would be appreciated!
Thanks.

Right now the issue isn't so much about the diameter of your barrel but rather the chamber dimensions and how deep your throat is. You could try seating the bullet a little bit deeper or compare the case mouth diameter of a fired cas to a loaded case. You are probably fighting a tight chamber neck or short throat and never would know if just shooting j words.

Interesting, i was wondering is OAL was a possible issue. I did check the chambered rounds for any indications of friction/marring contact. I will have to get some more factory ammo for the dimentions you suggested. Thanks for the suggestions!

Mookie, What mold are you using?

I'm using the NOE 454-350-RF-AD3 and the Lee C452-300-RF molds. Powder coated and sized to 0.452" they both chamber in my AR-15 and Mossberg Patriot Predator bolt gun. Feeding and cycling with the AR is not a problem but still working on getting acceptable groups.

I am using
NOE 454-270-SP dropping at 270 or 280ish
NOE 454-338-RF dropping at about 320 - 330ish.

When you size to .452 do the bullets load and extract without firing them?

I am thinking that once fired they would exyract and the throat is just tight on them now.

I will try sizing down to .452 and see if I still have extraction issues when executed manually.

I will also take a look at the extracter to ensure it is not just an issue there.

Thanks for the input!

Round OAL is 2.080. I have looked for signs of engagement on the bullets but have not seen any so far.

Sharpie to top half of a cartridge, chamber it and see where the cartridge is sticking.

Okay so i took another look at the ammo. First I tried cycling snap caps i have for it which it did without fail. Then i tried the dummy rounds I made for this particular bullet. These were made with dowel rods in the cases to keep bullet in place and RV silicone in the primer pocket. These again chambered and extracted just fine as well. Next I tried several rounds randomly and found that some chambered and extracted just fine. I then compared OAL between the dummy rounds, the rounds that did chamber and extract and the ones that did not. I found that OAL of 2.08 was too long and I needed an OAL of 2.06 and then all these rounds chambered and extracted!

Thanks for everyones input! Reminded me to check things I overlooked.

Thanks
Sean

Moleman, excellent suggestion, luckily figured it out before then!

What powder and charge weight are you guys using in the 450BM for cast bullets?

I used the loads for 325 gn cast bullet with H110 and 1680. Both had loads listed in the Lyman manual for the AR platform. I loaded several different powder charges by .5 gn inciments. Once i get to a range to test them i will try and find th e sweet spot and dial it in by .1 gn incements.

just started loading this caliber myself. i built the upper with the barrel CDNN had on sale for $100. plinking load so far is 255 grain lee 6 banger, sized .454 and coated with eastwood mirror red over 33 grains imr4227. defense load is same powder and charge weight with hornady 300 grain xtp. both shoot 2-3 inches at 200 meters. velocity listed at around 1800fps out of a 20" barrel. so far so good.