Apex barrel plunk test

[optimator]

I've been shooting BBI 147 coated bullets. With my factory barrel they would pass the test at 1.15. With the new barrel they won't plunk and spin until their at 1.10. Has this been the case for anyone else?

[want2race]

The Ogive is usually long on 147's. Do you have a standard 9mm chamber reamer? You could see if it drops in and spins free. Will likely catch on the rifling. I can check mine. Throat might be a bit tighter than stock.

[optimator]

I've been loading 3.1 gr of Titegroup at 1.15 with no problems. I'm concerned about pressure going down to 1.10

[Steve RA]

Many of the custom barrels have short chambers.

[optimator]

I loaded up 20 each with 2.9, 3.0 and 3.1 of TG at 1.105. No pressure signs with any of them. The 3.0 had the best accuracy of the three. This will be the load I use for this batch of BBI's. I need to dig around and see if I have any of the Acme 147's left. I'd like to compare the profile of the two.

[ddc]

somewhat apples and oranges but...

With Blue Bullets 147 RN and Apex SDI barrel:

1.160 obvious problem.

1.150 they will drop in and rotate with effort but I can feel them catching on the rifling; they are not "spinning", lol.

1.143 better than 1.150 but there can be some slight catching. Function fine in the my M&P with Apex SDI barrel.

1.140 drop and spin; this is my target length. Get some out to about 1.143. But those still function fine as previously indicated.

At 1.143 even though they catch a little when spinning, after multiple chamberings there is no setback.

[MemphisMechanic]

I throated my APEX SDI barrel. My three bullet profiles of choice in 135 - 147 grain profiles can all be loaded out to 1.150" now.

...Because a 135gr BBI coated bullet was going to have to be loaded around 1.100" otherwise.

[optimator]

I throated my APEX SDI barrel. My three bullet profiles of choice in 135 - 147 grain profiles can all be loaded out to 1.150" now.

...Because a 135gr BBI coated bullet was going to have to be loaded around 1.100" otherwise.

I'm considering getting mine done. I don't want to be limited on my bullet choices. But, I have never had this done before. Do I take my stock barrel to my gunsmith and tell him to "match this"?

[ryan45kim]

My Apex gunsmith fix barrel would not take my bayou 135s unless they were loaded under 1.100. 30 seconds with a throating reamer and I can load to 1.150 (my normal load). A throat reamer is $55 from brownells.

[want2race]

If you take it to a Gunsmith, take your ammo. Specify exactly what you want. It can literally by done in under 5 minutes.

To specify, the Apex chamber is not short, just a snug throat.

[MemphisMechanic]

I loaded my three preferred rounds (124 FMJ, 130gr FP, and a 135gr LRN) to the length I wanted the barrel throated to - that was 1.155"

I also loaded one of them to 1.120, 1.135. 1.145...

I used the last three rounds to monitor how quickly I was cutting the leade as I ran the reamer through it.

When I knew I was close, I went very very slowly until I hit 1.155" clearance - all three were just barely clear of the rifling, and the fattest profiled bullets would spin with the slightest bit of drag.

That way I can now load my ammo to 1.150" and have .005" clearance to ensure it'll feed 100%.

Side note: don't have them use your factory barrel as a guide. M&Ps have short, short chambers. Just buy the reamer for $55 and do it yourself.

Also, don't attempt to throat a hardened barrel like the factory M&P or an XD's with a chamber reamer. You'll just dull the reamer.

The Apex barrel cuts like butter, however.

[optimator]

Thanks for all the help guys. I've been shooting most of my life and reloading about 15 years. But, just a few calibers with pet loads that I never had any reason to vary from. Until I got bit by this 3 gun game... Since joining this forum I realize I don't know jack shit! But I'm catching on quick!