New loads are a bit long?

[upsdownsideways]

With factory ammo (Hornady), I can put a round in the chamber and it closes no problem.

With my new load (Lapua with Beger 140 hybrids), I can't. When I go to close the bolt the round hits the part just below the chamber. I have to manually put the round partially into the chamber and it closes no problem.

The COAL is 2.860", which fits in a magazine no problem, but doesn't close. Is it the hybrid bullets giving me a problem? Not seating far enough? Or both?

Edit: Corrected terms.

 

[CoryT]

Let's see if we can't parse this out to correct terminology. I don't believe you are referring to the throat, but the chamber. The throat is the area ahead of the chamber where it transitions to the rifling. If the load was too long for the throat, it would not allow you to close the bolt without some effort and would leave marks from the rifling on the bullets.

As you do not state the actual caliber, I'm guessing 6.5 C or .260 Rem based on the bullet and loaded length. While this may fit in the magazine, it may be too long for the action, and would be over max SAMMI length for the cartridge (2.825 and 2.8 respectively). The extra length could cause a bind between the magazine feed lips and the bullet tip, as the case does not feed forward far enough before the tip strikes the feed ramp and then gets pinned at the rear of the chamber edge, which seems to better match your description of the problem. What is the overall length of the Hornady rounds? I'd reseat to that length and see if that solves your problem.

 

[upsdownsideways]

Let's see if we can't parse this out to correct terminology. I don't believe you are referring to the throat, but the chamber. The throat is the area ahead of the chamber where it transitions to the rifling. If the load was too long for the throat, it would not allow you to close the bolt without some effort and would leave marks from the rifling on the bullets.

As you do not state the actual caliber, I'm guessing 6.5 C or .260 Rem based on the bullet and loaded length. While this may fit in the magazine, it may be too long for the action, and would be over max SAMMI length for the cartridge (2.825 and 2.8 respectively). The extra length could cause a bind between the magazine feed lips and the bullet tip, as the case does not feed forward far enough before the tip strikes the feed ramp and then gets pinned at the rear of the chamber edge, which seems to better match your description of the problem. What is the overall length of the Hornady rounds? I'd reseat to that length and see if that solves your problem.

Yes, my bad on the terminology, and correct, its a 6.5 CM.

Not sure on their length, but as the bullet in the Hornady isn't the same as the Berger, I wasnt sure if that could be the issue.

 

[CoryT]

Changing the bullet would nominally change the base to ogive measurement, but max COAL still applies. One can sometimes load longer that SAMMI max, but that is determined my experimentation with a particular setup, and is seems yours does not work. How did you decide on the 2.260 length ?

 

[upsdownsideways]

It was advised by some here to start there and work my way down. (2.860 was near the top of the COAL for the mag)

 

[CoryT]

Not generally good practice. I suggest you visit Dan Newberry's page on OCW load development. One should always first establish the point where the bullet engages the rifling and work back from there, as that will generate max pressure. There are a number of ways to do that, using the Hornady case gauge system, stripping the bolt and seating a test cartridge until the bolt drops closes, modifying a case by slitting the case neck then just starting the bullet in the case and closing the bolt to seat the bullet, direct measurement with the barrel off the receiver, I'm sure there are others.

Once max length is determined, you can find the max powder load by the loading manual and going up in small steps until you see pressure signs. that is the NEVER EXCEED load.

I normally start looking for an accurate load by seating .020 deeper that max length (deeper if required for mag feeding), find the powder weight that delivers the least vertical spread, then tune seating depth as a last step. I test vertical at 400 or 500, while checking velocity on the LabRadar.

 

[upsdownsideways]

Not generally good practice. I suggest you visit Dan Newberry's page on OCW load development. One should always first establish the point where the bullet engages the rifling and work back from there, as that will generate max pressure. There are a number of ways to do that, using the Hornady case gauge system, stripping the bolt and seating a test cartridge until the bolt drops closes, modifying a case by slitting the case neck then just starting the bullet in the case and closing the bolt to seat the bullet, direct measurement with the barrel off the receiver, I'm sure there are others.

Once max length is determined, you can find the max powder load by the loading manual and going up in small steps until you see pressure signs. that is the NEVER EXCEED load.

I normally start looking for an accurate load by seating .020 deeper that max length (deeper if required for mag feeding), find the powder weight that delivers the least vertical spread, then tune seating depth as a last step. I test vertical at 400 or 500, while checking velocity on the LabRadar.

I am limited by magazine size however, of which they recommended the 2.860 to start off and work my way back from.