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Discussion Starter #1
I have a Tikka 7 mag I am trying to load with 160gr accubonds with Imr 4350 and Imr 4831. I cannot get nowhere near the speed this bullet should be. I'm trying to get between 2900-3000fps. Accuracy is good but 2800-2850 is best I can get out of these powders. The nosler Trophy grade ammo is listed at almost 3000fps with this bullet but when I ran it through the chronograph it was only going 2714fps. My 7mm08 with 22 inch barrel is almost where the mag is. Do I need to get a different powder? Going through the nosler data I should be there with the Imr powders listed
 

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Well trkyman1 I would disagree with you sir about 2800-2850 not being nowhere near the speed desired of 2900-3000 fps. Your only 200 fps off.


Anytime your over 2500 fps I would not sweat the last couple hundred fps. My opinion, but I spend most of my time below 1600 fps, so what could I know?
But then I don't obsess about speed. Accuracy yes, speed no.


My advice, go back to start loads, look for accuracy.


FYI your nosler trophy grade ammo gave you a big clue. Maybe your bore is big and your losing gas around the bullet?

Maybe you should just accept that it is a 2700 fps rifle for whatever reason. The variables are many and widely varying.
 

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Discussion Starter #3
Then there would be no need for a 7 mag. The whole reason for the mag is to get the speed for long range shooting/hunting. Accuracy is not an issue with this gun. I'm no greenhorn to distant shooting as I compete in metallic silhouette. There is nothing wrong with the barrel as I can get 3000fps with a 162gr hornady factory load. My question is for experienced handloaders shooting this caliber.
 

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I started with 160's when first starting to reload for the 7 RM. Never found an accurate load. IMR 4831 was supposed to be the go to powder at that time. I switched to 175 gr with R22 and it all worked together with little effort. Velocity was as high compared to the 160's but the bc was much higher so that is what I've stuck with for the last 25 years. Great ballistics with little wind drift. Starting velocity is not as important as velocity and wind drift down range.
 

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You can take two brand new rifles off the rack that were made in the same factory on the same day and the rifle that had the rifling cut with a brand new broach will always shoot faster than a rifle made with a broach at the end of its life cycle. Hammer forged barrels are the same but to a lesser degree.....bottom line is that tooling used to put the rifling into a rifle wears out and it IS reflected in the end product!

How many rounds have been shot through your rifle? A 7 mm Mag...any 7mmm Mag is good for maybe 1500 rounds before severe throat erosion and barrel wear become apparent. The 7mm mag is a very inefficient round as are all cartridges with a large volume of powder being burned in a smaller diameter barrel. This velocity discrepancy that you are getting is always more apparent in inefficient overbore cases. I am a 243 Winchester fan and they are also overbore and inefficient only to a much lesser degree. I have three 243 rifles. With the same exact load shot in all three rifles the velocity variance is greater than what you are getting compared to the published data that you are using. My newer TC Compass 243 gets 3900 fps with my load shooting a Hornady 58 grain Vmax. My old tang safety Ruger 77 in 243 gets 3575 with the same load.

Incadently, the last coyote that I killed was killed with the old Ruger.....he didn't seem to notice the velocity difference.

Another thing to consider is marketing hype. Factory loaded ammo very seldom shoots through a chronograph to the advertised velocity. Speed sells period. They never write on the box what gun they used to reach their printed results. Most likely they are using a universal receiver with a barrel longer than on a hunting rifle to accomplish their printed velocity.

I used to wring out every bit of FPS that I could get. However in the last 25 years or so I have focused on accuracy over velocity and have killed more stuff.
 

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My experience with a 7 Mag is they like slow powders. My Browning BPR loved Reloader 25 and 175 gr bullets. Bullets weighing 140-150 gr with several other powders were meh. I think R25 is now R26. That would be my choice with your 160 gr bullets.
 

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Discussion Starter #7
I was going to buy rel-22 but I already had the others. It seems a lot of guys are using rel-22 or h-1000. One of the reasons I did not buy rel-22 was they were saying it is very temp. sensitive. Not sure if it is but just fishing around to see what others have success with. Thanks for the input. My gun is very accurate with almost anything I shot so far.
 

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Way back when the 7mm mag came out all of the new powders were not around yet. IMR 4831 was what I used. I am now back into shooting the 7mm mag and like Retumbo and H1000 with the bigger bullets!

I am not a target shooter but MOA is easily obtained when I do my part. I like the Hornady 162 and that high BC!

My whole reason for getting back into the 7mm mag is that coyotes around here have adapted to the hunting pressure pretty well. They like to hang up out there at the quarter mile mark and beyond. My little 243 with its 58 grain v maxes is running out of poop real fast by then plus they blow around pretty bad. The 7 mag should even the playing field a bunch.
 

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The Hodgdon website lists 59.5 gr of IMR 4350 is max load for the 160 gr. 2,850 fps. That is not their best powder for velocity.

IMR 8133, Re26 and a few others show more than 3,000 fps with their max loads. Not sure which bullet you are wanting to use. I noticed a lot of variation in the Alliant data for maximum powder charge (using Re26) among the different 160 gr bullets they tested.
 

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im with 45/70 try some re25 or even 7828sc which is my favorite powder in the 7 mag. 4350 is definitely on the fast burning side for heavies in the 7 mag. Even 4831 is to fast in my opinion for anything heavier then 140s. Also if you want speed in the 7 mag you need at least a 26 inch barrel. Longer is even better. Most of the load data that isn't total bs in the books is shot with 28 inch test barrels. every inch of barrel in something like the 7 mag will net you about a 100 fps so 2 more inches of barrel and youd be there.
 

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I hope you solve your problem. My magnum affinity was solved by an orthopedic surgeon. I have had four rotator repairs, and all were separations. Ouch.

I have not picked up my 7mm Rem mag or my 300 WSM in ten years. My deer rifle is now a 7mm-08. Even my beloved 30-06, 308, 270, 25-06, and 280 stay in the rack.
 

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I had the best luck using Retumbo with the 160 grain Accubonds. I don't have my data in front of me right now but I believe I was shooting the max listed load from the Nosler manual and I know I used Remington brass with a Federal 215 primer. This also happened to be the most accurate in my particular rifle, well under MOA , the rifle has long since gone down the road but I kept the barrel because it shot so well.
 

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Discussion Starter #13
I got some rel-26 and all is well. No problem getting the velocity with the accubond now. I was actually over 3000fps and settled on 2950-2975 with two cutting the same hole and one a half inch from the two. I repeated this group twice and am satisfied. Thanks for all the help.
 
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