7mm REM Mag - Ruger issue

[The Outlaw Kyle]

Hi everybody. I'm new here. JD338 suggested I try this place out, so I look forward to learning from you fine gents. Lets get on to the issue:

I'm reloading for a couple of other peoples rifles. One has a Browning A-Bolt Gold Medallion, the other a Ruger M77, both in 7mm Rem Mag. The Browning is recent manufacture, around 2004. The Ruger was made in 1971. I'm using Nosler 140gr Ballistic tips for both. When I used my stoney point gauge to get the OAL max for both, I got the following numbers:

Browning: 3.299 measured
Ruger: 3.4365 measured

Based on the reloading data I have seen for the 140gr, the OAL should be 3.270 (min?) for a 7mm Mag. My question to you is as follows:

1. Is the Ruger chamber way out of spec?
2. With the chamber being about .165 over sized should I simply load to the min OAL and what ever accuracy I get, I get?
3. Or, can I truly push the bullet out to 3.400 OAL? Will I get lower then desired pressures, or something else bad?

Thanks for any help with this. It really surprised me when I saw those numbers. I re checked it 3 more times, and got within .005 each time.

TOK

 

[JD338]

The Outlaw Kyle

Welcome to the forum, glad you are here.

I can't speak to your measurements but different manufactures do indeed have different lengths (freebore). I am confident that both rifles are in spec for their design.

I would load for each rifle separately, loading off the lands or to just under the max magazine length dimension. I have had my best accuracy with BT's from .015" to .020" off the lands. My RUM has a lot of freebore so I just load my COL to feed through the magazine. Accuracy is just fine.

What powder are you using and what kind of accuracy are you getting?

JD338

 

[Antelope_Sniper]

Outlaw, glad to see a new member.

There are several .270 Winchesters in my house, and I also use the stoney points gauge. My wife's Tikka has .25 less frebore with NBT's then my Winchester. Both shoot sub 1/2 MOA groups.

We worked up a load for my cousins 7mm that shot really well. I included 150gr BT, and H4831. Sorry I don't remember exactly what primers we used, but they would of been either CCI200, or WMRP.

 

[FOTIS]

Browning: 3.299 measured
Ruger: 3.4365 measured

Based on the reloading data I have seen for the 140gr, the OAL should be 3.270 (min?) for a 7mm Mag. My question to you is as follows:

1. Is the Ruger chamber way out of spec?
2. With the chamber being about .165 over sized should I simply load to the min OAL and what ever accuracy I get, I get?
3. Or, can I truly push the bullet out to 3.400 OAL? Will I get lower then desired pressures, or something else bad?

Thanks for any help with this. It really surprised me when I saw those numbers. I re checked it 3 more times, and got within .005 each time.

TOK

Welcome to the forum Kyle. Glad to have you aboard. To answer your questions.

1. Doubt it. All manufacturers are different in their specs. Not necessarily wrong.
2. Load all bullets as close to the lands as possible (mine arre loaded 10 thousand of the lands or as magazines will allow. The longer the better....usually.

What are your loads btw?

 

[The Outlaw Kyle]

As far as powder goes, I am using IMR 4831, but I have some H1000 that I used for a 7mm RUM I may play around with after these. I haven't fired any of this ammo yet, so no answer on accuracy at this time, but I will report back when I do. Thanks for your help.

TOK

 

[The Outlaw Kyle]

Loads are 62 and 63 grains of IMR 4831. Again, haven't tried them as of yet. Just getting worked up, and see what flies with each rifle.

 

[JD338]

The Outlaw Kyle

Take a look at RL 22. :wink:

JD338

 

[6ppcar]

What JD said plus take a hard look at H4831 , IMR 7828 and RL 19. When all else fails you use IMR 4350 or H4350. Seat the bullets just off the lands if the magazine will permit.
Welcome to the forum.

 

[J300UM]

Take a look at RL 22. :wink:

JD338

+1 63-66 grains seems to be the best range of powder. I load 63gr for a rem. 700 and 65gr for a savage 110. 3.290 coal for both and both will shoot .5" all day as long as shooters do their part. Keep us posted!!!

 

[remingtonman_25_06]

Nother vote for RL-22 w/140 or 160's.

I use 68.5g w/140's NBT's 3250fps and 61g w/160g AB at 2900fps. These shoot 1/4 to 1/2 MOA out of my Rem 700 7 RM.

My rounds are loaded to 3.350" which are right on the lands of my rem 700.

 

[YoteSmoker]

63.5 IMR 4350 140 BTip Fed 215M 3100 FPS
63.0 160 RL-22 160 Partition and AccuBond 2911 FPS
Works great in my Model 70 with 26" barrel

 

[YoteSmoker]

Oh yeah, both are loaded to SAAMI 3.290 and both will shoot five shots touching under a half inch.

 

[bullet]

Load just under the length of you mag box, welcome to the forum.

 

[buckfever]

Nothing wrong with that Ruger I have a Remington M700 that I load to a oal of 3.500 with that bullet seated out that far you get a little more powder capacity so you get a little more velocity. Its really nice for those long 160 ABs.

 

[old #7]

Hi everybody. I'm new here. JD338 suggested I try this place out, so I look forward to learning from you fine gents. Lets get on to the issue:

I'm reloading for a couple of other peoples rifles. One has a Browning A-Bolt Gold Medallion, the other a Ruger M77, both in 7mm Rem Mag. The Browning is recent manufacture, around 2004. The Ruger was made in 1971. I'm using Nosler 140gr Ballistic tips for both. When I used my stoney point gauge to get the OAL max for both, I got the following numbers:

Browning: 3.299 measured
Ruger: 3.4365 measured

Based on the reloading data I have seen for the 140gr, the OAL should be 3.270 (min?) for a 7mm Mag. My question to you is as follows:

1. Is the Ruger chamber way out of spec?
2. With the chamber being about .165 over sized should I simply load to the min OAL and what ever accuracy I get, I get?
3. Or, can I truly push the bullet out to 3.400 OAL? Will I get lower then desired pressures, or something else bad?

Thanks for any help with this. It really surprised me when I saw those numbers. I re checked it 3 more times, and got within .005 each time.

TOK

Well first welcome to the forum.
All rifle manufactures have different amounts of freebore.
I have found that my rifles shoot the best when the bullet is seated from .030 to .010 from the lands.
I usually experiment with powder types and loads first and finish off the load with oal testing.
Durring the powder trial period I load to .030 off the lands.
After I find the most accurate powder I will seat the bullet closer to the lands in .005 increments.
I have had groups go from 1.5 to .5 (@ 100yds) with a col adjustment.

 

[The Outlaw Kyle]

I finally got out to the range this weekend with my buddies 7mm. I ended up doing a OAL of 3.275, which was about as far out as I could go and get good feeding. It grouped about the same with 63 and 65 gr of IMR4895. Velocities were 2800 and 3000 respectively. Is there a specific velocity I should try to hit with my 140 gr ballistic tips? Thanks for all your help every one.

 

[JD338]

The Outlaw Kyle

The BT is designed to expand from 3000- 1600 fps impact velocity. I have used the 140 gr BT in a 280 Remington at just under 3000 fps and it kills WT deer like lighting.
If you have two loads that shoot with the same accuracy and you are satisfied with the accuracy level, than go with the higher speed.

JD338

 

[FOTIS]

My 120 bt's (7mm) are tough as hell! I have shot a lot of animals and retrieved one in perfect mushroom that traversed the body of a buck at 300+ yards.