7mm rem mag velocity

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by upacreek, Jan 10, 2013.

  1. upacreek

    upacreek Well-Known Member

    Messages:
    245
    Joined:
    Dec 6, 2012
    New here, I don't know if this is the right forum. After a ton of reading I am puzzled why my velocities aren't higher. I had a new 26" shilen barrel installed a while back. I have tried imr4831, rotumbo, RL22, RL25, all as high as 1gr above max. None can move a 162SST above 2800fps. The chamber was cut wrong and has like .100" freebore. I have de-fouled the barrel several times trying to get different results. I was going to toss the barrel and buy a new one when my new gun smith suggested cutting the barrel back .200" and rechamber. I don't want to invest in a barrel I don't have confidence in and low velocities. The old 24" barrel used to shoot 160 game kings 3050fps and 1.5" group at 200 yrds. The shilen can't make a 4" group at 100 yrds, at less than 2800fps. Should I rechamber, or follow my gut and buy a lilja?
     
  2. Lefty7mmstw

    Lefty7mmstw Well-Known Member

    Messages:
    4,280
    Joined:
    May 13, 2012
    All barrels are different, and quite frankly I'm pushing my 7rem(factory 26") to get much over 3K with a 150 and 3100 fps with a 140. I'm using 7828 on 150's and I went to 4064 on the 140's for accuracy reasons and the dang thing didn't go more than a few fps faster with slower burning powder anyway.
    I'd think about re-chambering to 7stw as the boiler room will help with speed more than pushing your 7rem hard.

    I re-read the end of your post, and I'd wrap the barrel around a fence-post if it won't shoot. I would still think about 7stw.
     

  3. lloydsmale

    lloydsmale Well-Known Member

    Messages:
    991
    Joined:
    Feb 5, 2012
    because chronographs dont like and loading manuals do.
     
  4. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004
    Velocity and free bore go hand and hand and .100 free bore with the 162 may not be enough.

    First I would recomend just cutting a new SAAME chamber just enough to clean up the old one
    and set back the shoulder Buy one thread (1/16 th) this should correct the chamber problem and save the barrel.

    Shilen makes good barrels and if you have a "Select Match" there should be nothing wrong with
    It. However there chambering leaves something to be desired and if they chambered it It is
    possible that you could have a bad chamber.

    Lilja Is my number one choice of barrels and if you decide to change barrels you can,t go wrong
    with one of his barrels.

    I always recommends using a SAMME reamer unless you know an extremely lot about reloading,
    to avoid problems. Load your ammo to fit in your magazine and there should be no problems and
    don't worry about how much case capacity is used up with the big bullets. (Faster powders will
    compensate for this).

    H 4831 was allways my favorite powder for the 7 mm rem mag and velocities were very good.
    (The standard factory load was a 140 grain bullet at 3175 ft/sec in a 26" barrel.) Most factory
    rifles would be pressed to do 3125 ft/sec with this load.

    Custom barrels should come close to this with the 140s but larger bullets will be noticeable slower
    in 24" tubes. I had a match rifle in 7mm RM that had a 31" shilen select match barrel for shooting
    1000 yard matches that with the case loaded "Very Hot" Would produce 3154 ft/sec with a 168 grain
    SMK using H 4831.

    If after the barrel is changed or fixed, it doesn't shoot well try another bullet. (Some barrels
    just dont like every bullet and some experimenting has to be done).

    Maybe this will help.

    J E CUSTOM
     
  5. upacreek

    upacreek Well-Known Member

    Messages:
    245
    Joined:
    Dec 6, 2012
    So back in '98 I really played with many bullets and loads. Finally found the combo that worked. 160 game king 3050fps and 1.5" at 200yrds. For 5 years, I could dial that in before elk season and kill what I aimed at. When my dad killed his 7x8 bull he ran out of shells (5) shooting 620yrds. I handed him mine and 3 rounds later had a flat elk. He only missed 2 times, but his 270 just didn't pack enough load at that range. My gun was accurate enough to hit twice in the neck and once in the back. In '04 the gun just would not dial in to better than 3" at 200 yrds (I used the gun whistle pig hunting in the spring). I missed a large elk ranged at 620yrds that year. I know I hit him he just didn't fall. I never recovered that elk. First elk in 14 years of hunting that I hit and didn't take home. I was sickened. After that considered 300win mag, but every elk (except this year) I have ever killed were with the 7mmRM my dad gave me when I was 11. I don't want to give up on the gun for that reason. 8 out of 10 elk I have shot were between 400 and 550 yards. Due to my experience in '04 I have been leaning toward 175 sierra or 180 berger for elk. The game kings run around .430BC and I want more confidence beyond 500yrds. The Shilen is 1/9 twist, 26". I have tried 160GK, 162SST's, 175 sierras, 180 bergers between 2500 and 2825fps. Every load shot in groups of 5, chonographed, recorded results. Several poweders at many different charges. The old brass doesn't even think about going into the new chamber, but the new chamber has dark black powder burns at the neck on every case shot through it. All new Winchester brass has been used. Primer pockets cleaned and uniform, full sizing done. Tried different set backs on the bullet from 'almost don't fit in the mag' to deep in the case (relative to 7mmRM). Because I cannot ever get the bullet near the lands I wonder if that is some of my accuracy problems. I do not know who chambered the barrel, shilen or my gun smith. I am not impressed with it though. I also have a 7mmWSM. Not super accurate, but fun to shoot. Manuals indicate the REM MAG could have better velocities than the WSM. Any one have real experience with these two? I am not convinced on the WSM yet, though it killed last years elk.
     
  6. lloydsmale

    lloydsmale Well-Known Member

    Messages:
    991
    Joined:
    Feb 5, 2012
    id consider passing on those shots your not absolutely sure your going to make a vital shot the FIRST time. A gun and load accurate enough to hit twice in the neck and once in the back IS NOT accurate enough for that range. I know this is a long range forum but not everyone is capable of shooting live animals at 600 yards no matter what equiptment or load they use. I personaly wont take a shot on a live animal past 500 yards. I know my skill level and am the first to admit i have limitations. Im not try to critisize you. Just maybe give you a differnt perspective on what your doing.
     
  7. upacreek

    upacreek Well-Known Member

    Messages:
    245
    Joined:
    Dec 6, 2012
    Maybe I should clarify. I want my rifle to be accurate so I can have the same or more confidence that I used to have. I paid to have a new barrel due to the gun not performing. It literally cut my shooting distance down to 200 yards by time the old barrel was removed. I have shot several guns out of the box that shot as well as mine did when I gave up on the barrel. After I bought the shilen barrel I had a bedded down bull that I could not get closer to than 630 yards due to terrain. I could not take the shot no matter how bad I wanted to mount the bull on my wall and his meat in the freezer. Another hunter shot from around 800 yards 13 times and wounded the elk. I met the guy this season and ripped him pretty hard about his unethical shot. Latter that season he fired 8 times at a spike 550 yards to kill it. I have been in the same area for 19 years and know it well. Please don't mistake me for being the guy who takes shots due to lack of stalking skills or knowledge of the animal. As far as my dad's shot I would not have made that shot myself, but it was deep in a revine bedded down in the only clearing and due to how steep the terrain getting closer was not good in his opinion. I have no idea what he was aiming at other than he was concerned the elk's head was still up and he left his shells at the horse 100 yrds away.
    I stated earlier that in 14 years of hunting elk I have only wounded one that didn't come home with me. I was sick. I admit it was my error and bad judgment. Out of 11 elk recovered only 2 had non fatal shots for the first shot. Of the ones that had 2 holes the second was just a follow up shot to finish what was not a flat elk. Only 2 have required more than 2 holes. I am not saying that I am the best, I have a lot to learn. I have been very happy with game kings as they just plain take elk down right now in their tracks. I would like, however, to up my skill to the next level. I want to stretch out another 100 yards past what I had extensive practice shooting. To be honest I see shots or hear about them out 8-9-1200yards and I want to say its horrible, but I am hopeful one day I can get to that level. My dad, bless his heart, raised me in hunting and uses the 'instinctive' technique in which he is very effective with. I am a little more technical and want prescision. My question was related to the barrel that I have now shoots at a lower velocity (by 2-300fps) than my old barrel. I don't know if it's the chamber or the barrel, but its not right. I came here looking to get input as to my next move. I am not offended by your concern, I share your concern. I won't be satisfied until I can knock over 6" plates at 600yards 8 out of 10 shots. That is what I used to do at 500 yards. Any hope my WSM could ever out perform the RM? I don't know if I should invest in the WSM or sell it. Any input is appreciated.
     
  8. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004
    I have both the 7mm RM and the 7 WSM and the only time the WSM comes close or even with the
    7 RM is with the 140 to 150 grain bullets. the 7 RM has an edge with the larger bullets.

    Elk At 600+ yards is asking a lot of the 7mm Mag and second shots are to be expected.

    This is the distance that a big 30 comes into its own and the 338s are even better.

    J E CUSTOM
     
  9. upacreek

    upacreek Well-Known Member

    Messages:
    245
    Joined:
    Dec 6, 2012
    I agree that's a lot of distance for a 7mm. Two years ago I shot an elk ranged at 528yrds. Two holes, one in the vitals where I aimed. He laid down 10 feet away and I planted another in the neck. He was angled away from me and the bullet went a little higher than I expected. Once I dug the bullets out it was clear that the 160 game kings were not exploding like they do at 350 and 400 yrds. They both seemed to stay together more than I had seen before. I have never shot any thing lighter than 160's except 100 rounds of 100gr varmit I shot whistle pigs with. After that elk and the one I lost I have decided to go heavier. I do not know personally how the 175 sierra will knock down an elk or a berger 180. I hope they get the job done quickly as I hate tracking wounded elk. My brother in law keeps me in good practice with tracking.

    Back to my original question....any one have input as to the slow velocities the shilen barrel is producing? The gun smith I have decided on claims this barrel can be saved, I am not convinced. Any one gonna tip me over on keeping it or pursue the lilja barrel?
     
  10. lloydsmale

    lloydsmale Well-Known Member

    Messages:
    991
    Joined:
    Feb 5, 2012
    speed wize your wsm may come close to the 7rem but will never pass it. Problem with pushing either so hard is your going to reduce barrel life and brass life will be non existant. If you truely need more then standard 7mag level loads look at a 7stw or a 7 ultra.
     
  11. roninflag

    roninflag Well-Known Member

    Messages:
    3,226
    Joined:
    Feb 27, 2006
    try 69.5 H-4831 and 140 accubond. if that doesn not shoot get a krieger.
     
  12. Dick Tinsley

    Dick Tinsley Well-Known Member

    Messages:
    381
    Joined:
    Mar 9, 2012
    This is just my 2cts! I've shot a 7 mm mag for a little over 30 yrs, I know an understand that every barrel an rifle, etc are differant. That being said, back 20 plus yrs ago the load I used in my 7 mag(24in barrel) was 64gr IMR 4350 cci 250 primer, WW brass. Was gettin about 3020 fps! Another load I'm using today is 71gr of H-1000, both loads are with a 160 grn Gamekings. Been shooting the 168 Bergers with the same load. I've never took the Gamekings over 600 yards but they do work well to that distance I know! If it was me( an everybody is differant ) from what I've been reading I think you have your heart set on a new barrel! If so make sure that you have confidence in your smith an feel comfortable with the decision you make! The 7 stw is a good round, the 7/300 win mag is also a good one too! Hope this helps, just my 2cts!

    DT
     
  13. MontanaRifleman

    MontanaRifleman Well-Known Member

    Messages:
    6,068
    Joined:
    May 21, 2008
    I have done a lot of loading for and hunting with the 7 RM, and you should be able to easily get 3000 fps with a 160 bullet out of a 24" bbl let alone a 26" bbl. You're freebore is on the short side and that will affect your velocity so re-reaming it may increase velocity, but... 4" groups would make me very leary. A good custom barrel shouldn't be very picky. Sometimes you get a bad one. I used 4831 with my 7mm and it worked well. If I were to load again for one I would try Retumbo and RL17.

    As for what cartridge to use for elk, a 7mm at LR is pushing the envelope a little and requires good placement. I would prefer a 300 mag of some sort.