450Bushmaster.net

For the record, my effort with the 240 XTP Mag was done using my original Bushmaster 20", 1:24, chrome lined bore upper with a carbine gas system. I have not revisited them since I got the Bartz upper. Thought I should clear that up.

How does the feeding issue with the 275 Barnes manifest? I typically load both the 200's and 275's to a COL around 2.19, in order to drive the taper crimp down into the front driving band groove. Even though the 275 is longer, seating the bullet to the middle driving band groove IIRC, yields a COL too long to fit in the magazine. I'm at work, so the last statement is running off of recollection.

Hoot

Hoot.

Sounds like I'm using the same upper you started with. I loaded the Barnes 275 tsx to fit the mag 2.225 I believe. Crimp to .474 and not into the relief band that was well inside the casing. After shooting the 250 FTx's loaded a couple 275 's into the mag. I hit the carrier release and the round didn't go into battery. Had to use the assist. I also had a couple that failed to feed properly right from the mag. I had to drop the mag then clear the round. This are the only FTF's I have had. the ftx and xtp have all fed and ejected without issues.

I have not loaded more then 3 into my mag yet while firing. I was reading your thread about the Bushmaster mags and lip tension but I dont think thats it as all other bullets have worked well. Perhaps the next time I shoot I will fully load the mag and see what happens.

Skinner

Hoot wrote:Of the bullets I have loaded the least, the 250 FTX is it. There's more than enough data around here for them already....snip...

Here's about as good as I can do with 250 FTX handloads. That's 5-shots at 100 yds. You'll be hard pressed getting a taper crimped into a flat jacket load to do much better than that. If the 250's had a cannelure, you might be able to improve upon it a little. Same BR setup, same scope I still use for load development.



Now just watch. Someone will post a better group.

Hoot

the 275 XPB has a third driving band that you can crimp into when loaded to around 2.20". The 275 TSX does not. The Barnes are tough bullets, probably hard to get a crimp when not in a driving band. I haven't tried because I load the TSX out to around 2.33". Need a windowed mag for that.

As to the feed problem, have you tried tweaking the feed lips so the rounds are pointed slightly up, and not straight.

You missed the bullseye! Just kidding, great grouping, shows the potential of this bullet and rifle. This is why I have 2-450BM's set up for specific bullets and dialed in to hit the bullseye. Incredible accuracy from a big bore!

I am loading the 275TSX bullets to the last groove and shooting amazing groups, with 40gr of LilGun