Deer Hunting Forums banner

New 8mm Rem Mag & Range Report

13K views 29 replies 5 participants last post by  CircuitRider 
#1 · (Edited)
Post Deleted
 
This post has been deleted
G
#9 ·
Well, today is revealing indeed all accept me changing my OAL and opening up my group to over twice the size it was Friday. You know, sometimes I need to leave somethings a lone. Now that said, here are my velocities from two different groups this morning and they are not over max (you can see by looking at my brass). I am going to adjust my OAL back to were it was 3.600" and continue to work up one tenth of a grain at a time till I get near or at max for my rifle.

Here are pictures of my chronograph readings, brass fired for highest velocity average and my group that needs the OAL adjusted back to where it was. This is very significant, considering I have a 24" barrel, and a greater cross section of my 200gr bullet than a 200gr bullet out of a 300Rum.







 
#12 ·
Yes, I am ready for part two of my load work using four different groups, two different powders and two different bullets for a total of 20 rounds to be fired at the range Monday morning.


First: a five shot group using Sierra 220gr with Magnum and a five shot group using Nosler 20gr Accubond with IMR7828

Second:
a five shot group using Sierra 220gr with IMR7828 and a five shot group using Nosler 200gr Accubond with Magnum
 
#13 · (Edited)
Today was an interesting morning but you talk about hot and humid. Once again to remind everyone, this is an out of the box rifle with no glass bedding or pillar bedding and this rifle uses a pressure point up close to the end of the for end. No, I do not have any intention of changing it at the moment. But today was a very good day of discovery. First, 200gr Accubonds give me great velocities but the accuracy is very poor. I have tried now different loads with RL-25, RL-22, MRP, Magnum and IMR7828 and the groups are embarrassing to say the least. My rifle simply does not like them. I have 100 200gr Accubonds left and will trade them for some 200gr Partitions if someone is willing to do so, and if you are willing please pm me about trading.

Magnum powder preformed well, my barrel did not get as hot to the touch as with the other powders and accuracy was fair to good but average velocities were 2951fps with the 220gr and that was disappointing. Now IMR7828 did very well in velocity with the 220gr SBT and accuracy was good and this was with one grain under book max. I am very please with this powder and the Sierra SBT. I will be soon testing 250gr bullets and also some 200gr (forgive me for even using these words and don't remind me of my dislike for terminal results I get with the :mrgreen: - Barnes TSX).


220gr SBT, 83.0grs IMR7828, Rem brass, Rem 9 1/2M primers, 3016fps, OAL 3.600" .964 minus first round which was first round out of a clean barrel. After ten shoots this group should tighten up a little more once the barrel is fouled good.



 
#14 ·
Man, this 250gr Barnes orginial in 8mm sure makes the Sierra 220gr SBT look anemic. :shock: Can't wait to work with this bullet, but that will be when the weather get just a little cooler. :mrgreen:

What a cool looking beast and if I can get around 2800fps (hopfully) WOW!
 
#15 ·
Well, I did some more range work with my 8mm Rem Mag and I have discovered that my rifle does not like 200gr Accubonds or Partitions, but does like 220gr Sierra and 250gr Barnes Originals.
First: The 200gr Accubonds will give me 3154fps and the Partitions will give me 3137fps. These are awesome velocities but accuracy is not acceptable to me running 1 ¾” at best to 3 ¼” for most groups.



Second: The 220gr Sierra SBT gave me last time I was at the range working with this bullet 3016fps on the average. This time 3018fps on the average with 21 Extreme Spread and 9 Deviation and a three shot group size of .487” – This was the seventh and last group I fired and still had this level of accuracy after all that recoil. The first group I fried was after one fouling round from a clean barrel and it was a three shot group that was .849” and it had an Extreme Spread of 20 and a Deviation of 9 giving me 3017fps.
Three shot group .487", 220gr Sierra SBT, 3018fps average

Three shot group .849", 220gr Sierra SBT, 3017fps
 
#16 ·
Third: There were the two groups I fired using the 250gr Barnes and was 5% with below published max with one group and 4% below max with the other group, giving me from 2701 – 2720fps as I was testing in the margin of safety to make sure I did not get close to max pressures with this very soft bullet. Of course I will now increase my charges moving toward max hoping to be over 2750 – 2800fps with an accurate load. Group sizes were as follows as I increased the powder charge from 5% to 4% below max. Best group was .447” with Extreme Spread of 22 and Deviation of 11, and worst group was .8485” with Extreme Spread of 22 and Deviation of 11.
Three shot group .447", 250gr Barnes Original 2720fps

Three shot group .8485" , 250gr Barnes Original 2701fps
 
G
#17 ·
Today I decided to test my extended load work with my hunting load for my 8mm Rem mag and also looking for better velocities for my 250gr Barnes Original. My average today with the 220gr Sierra was 3003fps and this is due to me using after I full sized my brass an expander mandrel expanding the diamater of the neck .002 and then using the regular mandrel for my Sinclair neck turner. This reduced the neck tension which also reduced my pressures and velocities from 3018fps on average to 3003fps but group is much tighter. Was able to get the 250gr Barnes Original to 2749fps and what was amazing today was all three of the rounds were 2749fps.







 
#18 · (Edited)
According to Q/L the 180gr GS Custom has a BC .463, 4175ft pounds of energy at muzzle using IMR7828, still 2000ft pounds of energy at 560yds, 2.4" high at 100yds with a zero of 270yds, -5 at 350yds not bad not bad at all - plus still moving at 2174fps at 600yds and the GS will open up at 1500/1600fps (these ballistics are calculated at 4,000ft the lowest elevation I will encounter in Arizona where I am thinking about using them).

Now if GS will return my email about a USA distributor since they are setting up shop in the USA to manufacture the GS Custom I will get them faster. The GS out performed the TSX and TTSX in my 257Wby and 30-06 on terminal results on deer when I used them alternating between the two bullets during a 3yr period. Also, I have been able so far with 200gr, 220gr and 250gr bullets to duplicate with my Big 8 the velocities Q/L estimated and in one case even higher velocities. This will be truly interesting when I get some.
 
#19 ·
Well, I have my name added to GS Custom Bullet list to notify when they start production in the US. I will wait till then, the prices are to high for the bullets shipped from South Africa. Including shipping from South Africa for a box of 180gr is 87.00 and one box of the 170gr is 83.00 and I would need at least two boxes of either one to do proper load work and have enough for practice at distance and final sight-in. I will wait!
 
#24 ·
Full length pressure bedding my 8mm Rem Mag
Expanding the recoil lug area.


Doing my final sanding of the barrel channel after expanding the recoil lug area.


The recoil area lug area turned out nice and there is now no movement like I experienced before I bedded the stock. Still have to trim a bit and clean it up some.

The stock needs set for another 12 hours and I will put the barrel in sometime tomorrow and then Monday morning will go and see how it shoots.
 
#25 ·
Well, the full bedding didn't improve the groups but is as good as they were. Here is a sample target. Also, this ends my work for now with the 8mm Rem Mag unless I take something this season with the rifle.

 
#26 ·
I Just Can't Leave It Alone :)
Well, I have decide to take a different direction with my 8mm Rem Mag.

One of my Ruger 30-06 wood blued Hawkeyes (I had more than one) and I had all kinds fo trouble with getting it to shoot, even pillar bedded it and it would not shoot then I bought a Hogue Over Mold stock with full bed aluminum block in green? Here is a picture of it in green and the Hogue stock got the 30-06 ruger shooting good.



 
#27 ·
Well, I do not want to damage my wood on some of my hunts that are usually rough on my guns especailly when I go up a grade or down a grade and slip on the rocks and occasionally ding my stock. I have decided to give it a try and bought a Hogue Over Mold long action full bed aluminum block stock in the same color as the one for my 30-06 and it should be here sometime the middle of next week. Here are pictures from the Hogue site but it is in gray. Also, the same Burris that was on the 30-06 is now on the 8mm Rem Mag because I put the FX II 6x36mm LR Duplex Leupold on my 7mm08 M48 TGR because my 6 power fixed Weaver gave up the ghost and will not adjust windage.














I am loaded and ready. I have 20 loads four 5 shot groups all with 220gr Sierra SBT, IMR7828, Rem brass, Rem 9 1/2M primers all trimed to the same length and the only difference is that two 5 shot groups have necks turned and two 5 shot groups don't. Want to see if it makes much difference. Run out should be much less since I am not using the RCBS seating die but a new Hornady Custom Grade new demension die set.
 
#28 · (Edited)
Well, my Hogue OverMold full bed block stock came in today. First, I decided to go with black instead of green and I think it looks good. Second, I had an option to full bed the rifle in the stock or make adjustments and free float it, but I decided to go with the full bedding job in light of the fact that the factory magnum barrel is thin and tapers down to muzzle quit a bit. Third, tomorrow morning will be the test to see if it stays fully bedded or I free float it.

Here are some pictures of my Remington 700 8mm Rem Mag in the Hogue stock.







 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top