Update Mag length v's feeding issues Berger VLD Target 140 Grain 6.5

[rockchalk06]

No wind today and temps in the 80's, so I hit the range this afternoon. Printed some great numbers, but I'm stumped on feeding issues.

Rifle: Bergara HMR in 6.5 stock
Mag: Bergara 5 round and 10 round Magpul
COAL: 2.859" to 2.874" or O-Give 2.203" to 2.218"
Bullets: VLD Target Berger 140's

I stuck with 40.9 grains and just adjusted seating depth. Jam on my HMR is 2.273" O-Give. To get them to load and stack in the mags freely, I had to seat down to 2.223". I came up with 2.218" as that gave what looked like plenty of room in the mags with zero hang ups.

Fast forward to today. Bolt all the way back, mag loaded with 5 rounds (both 5 and 10 round), it would not feed. Bolt hit the back of the case and forced it down and into the mag. I did not test this before I went to range. That is on me. Lesson learned.

What sucks ass is I loaded 2.218", 2.213:, 2.208 and 2.203" Until I hit 2.203", they would not feed worth a shit. 2.203" fed 4 out of five rounds. I had to feed the rifle individually. Normally, I would care less and just load down to get them to feed, but look at these numbers.
2.218/.305" 5 shot group/7.65 SD/Spread of 21
2.213/.442" 5 shot group/8.08 SD/Spread of 22
2.208/.561" 5 shot group/7.44 SD/Spread of 17
2.203/.988" 5 shot group/9.07 SD/Spread of 20

It looks like the deeper I go, the more the SD and group opened up. For what it's worth, same mags with some 123 Scenar's I tested that were much shorter, feed 100%. All my 140 SMK's feed fine.

What spins my head even further around, all of the brass was once fired Hornady Match that I ran through my FL Hornady Sizer, no bushing. I have yet to run them in my Forster Bump die with bushing to hopefully tighten them up.

Any suggestions?
Thanks in advance SH

 

[rockchalk06]

Looks like the nose of the bullet is is being caught under the feed ramp @ 2.218" down to 2.203". Seated down to 2.195" and it's just plenty to clear the bottom of the feed ramp.

 

[spife7980]

A dremel can save the day.

that’s looking up through a hollowed out mag in my rem700.

Non binder plate aics mags allow out to ~2.960, you need to grind away some of that overlapping feed ramp material though to allow it to feed up for any extra length over ~2.860 like you would get with a binder plate mag.
With magpul mags you are stuck to the shorter length, there are no nonbinder plate options for the plastic.

 

[rockchalk06]

Thanks for that. I'm not sure if I'm ready to go hacking up this rifle yet.

I ran them down and 2.197" feed 100% reliable. I put these over the chrono and see what I get before I go that route.

Is this something that's done often? Cutting a groove on the feed ramp?

 

[Can't group Jim]

I have the Bergara Pro in 6.5 and it comes from the factory with the groove already notched. Not sure why they don't do it on all of them?

 

[spife7980]

Is this something that's done often? Cutting a groove on the feed ramp?

It is when you find they shoot best at a length longer than the short mags can accommodate.

 

[rockchalk06]

I ran another 4 five shot groups over the chonro yesterday with 40.5 to 41.1 grains of H4350. Oddly, this rifle just loves 40.9 grains at most every seating depth. What I didn't like about seating at 2.197" were the groups. I had SD's ranging from 4.90 to 10.06 but the groups were .354" out to 1.498". 40.9 was the best at .354 with a SD under 5. This was jumping .076" with once fired Hornady Match brass full length sized.

It may be time to pull the stock.....

I do appreciate all the help

 

[FCS]

I ran another 4 five shot groups over the chonro yesterday with 40.5 to 41.1 grains of H4350. Oddly, this rifle just loves 40.9 grains at most every seating depth. What I didn't like about seating at 2.197" were the groups. I had SD's ranging from 4.90 to 10.06 but the groups were .354" out to 1.498". 40.9 was the best at .354 with a SD under 5. This was jumping .076" with once fired Hornady Match brass full length sized.

It may be time to pull the stock.....

I do appreciate all the help

What is the 40.9 gr load doing at distance?
Velocity?

Why putz any more? Load'em and shoot'em, preferably at distance.