7 rum/sendero lands???

[remingtonman_25_06]

Was trying to find where the lands would be tonight out of my 7 rum/sendero with 160 AB.

Pretty much what I'm finding is that the 160 AB is over 4.060" which barely leaves anything of the bullet in the case.

Does that seem right? Mag box is limited to 3.670" I'm gonna say, so that puts a guy almost .400" off lands??

Remington do this on purpose? And if so what's the reasoning if any behind it?

 

[Guy Miner]

Remington has a history of building the throats really long, pretty much like freebore. Why they do this - I'm not sure - but they do. I've never been able to touch the lands & grooves in a factory .308 Win Rem 700 with ammo loaded to magazine length.

I suspect it's to keep pressure from being too high when any dunderheaded handloader crams whatever bullet will fit into the case & chamber, but I'm just speculating there.

Don't worry too much about it - see how they shoot first. Noslers typically handle the "jump" pretty well, as do Sierras.

Guy

 

[DrMike]

That amount of freebore is not unheard of, especially in Remington rifles. I've been told it was a safety factor engineered into the rifles. I can't verify that fact, however.

 

[Richracer1]

No worries, my 7RUM is the same way, but is very accurate with 150ETs and 160ABs.

My COLs are:
150ET - 3.655
160AB - 3.635

Kind of interesting that the ET is closer to the lands than the AB.

 

[FOTIS]

I have never been able to and fit them in the mag

 

[JD338]

Jorey,

That sounds about right. Remington uses a lot of freebore for extra speed.
Load the 7 RUM to the max magazine length and call it good.
BTW, 93.0 grs Retumbo should get you to 3300 FPS with the 160 gr AB. Shoots flat as road kill buddy!

JD338

 

[Greg Nolan]

Ditto what JD338 said.

 

[SJB358]

I get the same thing in the Whelen. I can't touch the lands in my rifle with 250 PT's.. Doesn't seem to hurt anything though..

Jorey, lets see that rifle sing buddy! You have been holding out on us!

 

[Ridge_Runner]

remington stole the idea from weatherby, longer throat actualy increases case capacity, cause pressure doesn't get too high until the bullet hits the lands, bullet jump is not necasarily a bad thing.
RR

 

[remingtonman_25_06]

Well I loaded 3 loads up with some 160 ABs and Retumbo at 92/93/94g with a rem case and cci250 primer loaded to max mag length which was 3.670" far as I could tell.

Shot them last night out at jmads on a dead calm evening. 1st shot was bore sighter after switching the vx3 LR 6.5-20x over from my 7 RM. Was 2" high and right from point of aim just by taking bolt out and lining up the little hole on the target 100 yards away, not bad.

From a concrete bench and atop a lead sled, I wasn't rather impressed as far as first outing goes. Not being able reach lands is going to be pain in my butt I think...

92g went 2.4"
93g did 1.38"
94g was 1.45"

Was only able to crono the 92g load and it was averaging 3250, ran out of good light by time let barrel cool after 4 shots in 10 minutes and waiting for my dad and jake to shoot a load to get anymore accurate readings on the latter 2 loads.

No pressure signs on any loads, good thing, but I think 93 might be where I'm gonna tweak a bit..

Its doing classic 2 in 1 out on all 3 loads, but it put 2 within little over 1/2" on the 93 and 94 load so obviously seating depth changes are in order.

Think ill load up 2 more loads at 93g, and seat em .020" deeper at each load, so next 2 loads will be 3.650" and 3.630"

See what happens I guess

 

[FOTIS]

Good luck Buddy!

 

[Richracer1]

Well I loaded 3 loads up with some 160 ABs and Retumbo at 92/93/94g with a rem case and cci250 primer loaded to max mag length which was 3.670" far as I could tell.

Shot them last night out at jmads on a dead calm evening. 1st shot was bore sighter after switching the vx3 LR 6.5-20x over from my 7 RM. Was 2" high and right from point of aim just by taking bolt out and lining up the little hole on the target 100 yards away, not bad.

From a concrete bench and atop a lead sled, I wasn't rather impressed as far as first outing goes. Not being able reach lands is going to be pain in my butt I think...

92g went 2.4"
93g did 1.38"
94g was 1.45"

Was only able to crono the 92g load and it was averaging 3250, ran out of good light by time let barrel cool after 4 shots in 10 minutes and waiting for my dad and jake to shoot a load to get anymore accurate readings on the latter 2 loads.

No pressure signs on any loads, good thing, but I think 93 might be where I'm gonna tweak a bit..

Its doing classic 2 in 1 out on all 3 loads, but it put 2 within little over 1/2" on the 93 and 94 load so obviously seating depth changes are in order.

Think ill load up 2 more loads at 93g, and seat em .020" deeper at each load, so next 2 loads will be 3.650" and 3.630"

See what happens I guess

This is my 7RUM 160AB recipe:
Rem brass trimmed to 2.830"
GM215M primers
91gn of Retumbo
COL of 3.635" (Most of my RUM COLs w/AB bullets range from 3.630 to 6.640 if that tells you anything)
Sorry no velocity info

 

[remingtonman_25_06]

Well I tried both of the 93g retumbo/160 AB loads at 3.650" and 3.630" last night.

The 3.650" was nice triangle group that measured .8"

3.630" had 2 touching and threw 1 out about an 1", I didn't pull it.

I was however in a hurry last night, was running out of daylight and I was pretty tired.

I think 93g is gonna be the ticket, just have to fine tune the seating depth a bit more.

Might need stretch her out a bit and see how she does at the longer ranges with seating depth changes, little easier to tell sometimes then at 100 yards. This rifle won't even probly see a game animal under 200-300 as it is.

I'm thinking I should just load up about 5 more loads in .010" increments from 3.6"-3.650" as that's where its looking like she's gonna shoot the best. Will see about shooting them at 300-400 yards next time around.

 

[SJB358]

Stretch it Jorey! Quit babying that thing! Let it run!

Sounds like it is getting close. I know it'll be impressive when you get it up. Jake said he is still going to whoop your butt on the long range though! :twisted:

 

[remingtonman_25_06]

Yah he probly will, been shooting more then me at LR a lot lately. I haven't had the rifle, time or money lately. Besides, that STW F'in shoots!!! Haha.

I will see how this 7 RUM turns out. If it doesn't do what I think or want it to, it may be going down the road to new home. I still have a 7 RM so not like I'm without a LR rifle...

I've got a hankering for a 375 RUM in a LSS I'm thinking...well see!!

 

[SJB358]

Yeah, you have the 7mm's covered pretty well, plus your Model 70 seems to be a great shooter Jorey.. I can see a 375 RUM being a pretty awesome rifle.

I do gotta say, Jakes STW is a great shooting rifle from what he shows us. Alot of HP right there.