7mm Rem Mag with RL-22...Help please
Hello,
I have been reloading, successfully, for my Model 70 Classic with BOSS for several years.
Recently, I used a friends chrono to verify the performance of my loads of 62.5 gr. of RL-22, CCI Mag primers, Winchester brass and Hornady 154 gr. SST bullets.
According to my Hornady manual, this is a max load and should produce velocities of ~2900fps. When chrono was used, I am only getting 2800 fps. I know the chrono is accurate based on other caliber data I have collected.
The loads are extremely accurate but I know I am not shooting to the rifle's potential.
I plan to send my scope to Leupold for ballisticall matched CDS dials but want to get my velocity back up around 3000-3100fps before getting scope work done.
Any info or comments on how to proceed and what I can really do with RL-22 is appreciated.
By the way, I just bought a very clean Model 70 Laredo in 300 Win Mag and any insight to load data for it woul be great!!
Thank you
I have been reloading, successfully, for my Model 70 Classic with BOSS for several years.
Recently, I used a friends chrono to verify the performance of my loads of 62.5 gr. of RL-22, CCI Mag primers, Winchester brass and Hornady 154 gr. SST bullets.
According to my Hornady manual, this is a max load and should produce velocities of ~2900fps. When chrono was used, I am only getting 2800 fps. I know the chrono is accurate based on other caliber data I have collected.
The loads are extremely accurate but I know I am not shooting to the rifle's potential.
I plan to send my scope to Leupold for ballisticall matched CDS dials but want to get my velocity back up around 3000-3100fps before getting scope work done.
Any info or comments on how to proceed and what I can really do with RL-22 is appreciated.
By the way, I just bought a very clean Model 70 Laredo in 300 Win Mag and any insight to load data for it woul be great!!
Thank you
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You don't mention the barrel length of your rifle which can easily account for 100 to 200 fps of velocity.Reloading info is often based on the longer, ie 24 to 26 inch barrel's. I too have the same caliber and components and 2800 fps with what you say is excellent accuracy would suit me fine. Personally I'd go with what you have now.Look at your bullet drop tables and you will see that 100 or so fsp in velocity doesn't add up to much. Just my opinion. 0 -
Speer no. 11 manual said they could detect differences in velocity due to throat erosion in as little as 150 shots-that's one hundred and fifty, not one thousand five hundred with a zero accidentally left off-with the 7mm Remington mag. 0 -
I think 100fps of the table is doing well. If you want to work up current load it may be worth a try. But a 154gr leaving the muzzle at 2800 will perform very well. Most likely unnoticeable through 400yds for hunting applications.
Just be cautious if you decide to work up, and go in small amounts.0 -
It's quite simple, really. Take your 2800 fps and divide by your powder charge of 62.5 gr. I get 44.8. Since your desired velocity is 2900 fps, divide 2900 by 44.8. I get 64.7. It will take 64.7 gr. of RL22 to get 2900 fps from your rifle. Now you have to decide if you feel comfortable with that load.
I like RL22 and use a lot of it. It's my favorite powder for 130 gr. .270 loads. I have four rifles in 7 Rem. Mag. and do not get the best accuracy with RL22, but I'm using heavier charges than you are. My rifles seem to shoot 150-160 gr bullets best with IMR7828 and RL25. I can understand your disappointment with your velocity readings since you can easily get even 2900 fps with a 150 gr bullet from a .30/06 or a .270 and why have a "Magnum" rifle if you're going to get .30/06 performance?
This puts me in mind of an article I read years ago by Jack O'Conner. His friend had a 7 Mag. rifle and constantly ragged O'Conner about Jack's antiquated .270. So they managed to get access to a chronograph and checked both rifles. Jack said, when they got the results, "His rifle was ruined!"0 -
Hello Mr. Ambrose with all due respect In reloading There is no direct relationship that 20% more powder will give 20% higher velocity or 5% more powder will give 5% more velocity . Smokeless powder is Progressive in their pressure generated. and digressive in there increase in Velocity . PLEASE never try to load unless a load is listed as SAFE pressure. 10% increase in powder may give 50% increase in pressure.. You may be asking for a KABOOM[V][:(!][xx(] 0 -
Thank you to all for the comments. My rifle has a 24" barrel without the BOSS. I LOVE this rifle but as mentioned, I would really like to get magnum performance from it versus 270/30-06 type performance.
It would not be a huge deal but I really want to get my ballistically matched scope for it. I just want to have the best performance when I send my info to Leupold.
Thanks again!0 -
tatasta,
There are many variables in working up a reload recipe.
1) powder type & quantity
2) bore size & degree of smoothness
3) volume of your brass (& chamber size)
4) seating depth of bullet
5) degree of fouling in the bore
6) bullet crimped or not
7) temperature of barrel & cartridge when fired
8) profile of the bullet (how much contact with the bore)
9) type of alloy in the bullet jacket (different alloys have a different friction coefficient)
10) twist rate
11) barrel length (the most obvious)
+ probably many more that others will add to the list.
All the above have a direct affect on velocity & pressure. It is not just fool-hardy but down right dangerous to fixate on one of the list & go beyond listed maximum loads.
Jim0 -
I've been reloading since the early 70s, excellent accuracy and within 100 fps of printed max would be fine by me. 0 -
I do realize all of those affect every aspect of performance.
I do not feel that I am being fool-hardy. I load for all of my guns below published max levels. Max load for RL-22 in my situation is 63.4 gr. I have never gone beyond 62.5 gr.
I am basically asking "should I be getting more out of my 7mm, with any given propellant and 154gr SST, than 2800 fps since I can go to Wal Mart an buy factory ammo that performs at 3100fps?" My rifle shoots factory ammo great too. 120gr. V-Max? deadly, 150 gr and 180 gr? deadly with BOSS tuned.
I am concerned about finding the best performance BEFORE I get a turret engraved. I have seen posted data of RL-22 in a 7mm RM as high as 68grs. Every book has a different max load. Who is right? I know how to load and watch for over-pressure da da da. I feel this is a safe and fair question that is not deserving of being called "fool-hardy". Why do some people feel so inclined to be condesending before knowing they are speaking to? Guess I just need a higher post count to have a brain.
"All the above have a direct affect on velocity & pressure. It is not just fool-hardy but down right dangerous to fixate on one of the list & go beyond listed maximum loads"
Was that not the original question?0 -
Speer No.9 said throat erosion can affect how much powder a rifle can take safely. They said eroded rifles took larger charges safely because it tends to lower velocity and pressure. It was in the section for the 7mm Rem Mag.
It doesn't look like we're any closer to solving it after nine replies so I'm gonna burn up your tenth. Buy that walmart ammo and chronograph it now, and don't go by how it shot when the rifle was new. Then you will know if throat erosion is cutting velocity. Throat erosion cuts velocity, and the more powder going through the bore the worse it is.
How many shots have you put through the rifle and do you pause and let it cool off between strings? It sounds like you've tried a whole bunch of factory loads and handloads as well as hunting with your rifle.
Frankly, I would either try the velocity with factory ammo which you tried before in the same gun when it was new, or have a gunsmith examine the throat with a borescope before I spent money having a turret engraved with marks that are only good for a barrel that may need replacing soon.
I have never shot out a rifle but I do believe that accuracy will also start to go south as the wear gets worse and worse, so it's not just a case of having to work up loads which restore full velocity.
P.S. I have looked into this topic a bit and sources on the web seem to say that double base, extruded powders are the hardest on the barrel (like RE22), followed by single base extruded, then ball powders. Some sources mention variation between two similar powders, such as IMR 4064 and 4895, as well.0 -
tatasta,
Here's the short and simple:
I don't believe in those scopes that require a supply of consistently manufactured ammunition in order to function. There are too many variables that can change over time that will render your scope obsolete. Get a good mil-dot or MOA scope, learn how to use one of those and forget about scopes dedicated to specific ammunition.
There are too many variables in equipment performance and reloading to make a judgment as to how fix your problem. Some of those variables have been named above but there are even more. You have to do the work of testing in order to see if your question can be answered.
If you believe that you can get higher velocities safely, go and do more testing. If as you say, you are aware of the signs of over-pressure, you should be able to finish up the testing in short order and then get your scope dials made.
Manuals are written for the average which will cover a huge spectrum of situations. They are not absolutes, they are designed to accommodate the range of reloading experiences also. You need to take that information as a guide for your testing. Be aware of the signs of high pressure and use a chronograph as collateral. I don't trust most consumer chronographs because they are prone to be inconsistent based on variety of conditions as well as operator set up and error which will have an effect on the readings. Your friend's chronograph may be accurate but it is more likely just consistently inaccurate.
If you can buy commercially manufactured ammunition at higher velocities that has the accuracy you require, the solution is to buy that ammunition and go shoot. Reloading for that rifle then becomes superfluous. Match your scope dials to that ammunition and hope that the manufacturer doesn't change his formula or stop making that recipe of components.
Best.0
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