shot today: 338 rum and edge-have ???'s

[lamiglas]

I went shooting today with a coupld of buddies. i shot my edge, (30 inch tube) Brad shot a sporter wieght 338 Rum, built by shawn (26 in tube) and Pat was shooting an off the shelf 338 win mag.

We had a great time, and pat had the best group (2 shots) of the day at under an inch center to center at 621 yds!

He has an edge on order and i cant wait to see what he will do with that!

Brad shot the best group when distance is included with an incredible 1.75 inch center to center at 910 yards!!!! the wind was blowing and there was mirage etc, i am still not sure how he did it, but i saw it so i am forced to believe it!!

anyway, here is my question. We are both shooting 300 smk's and we are both using 90 grains of H-1000. Is this to hot for a RUM?

primers were a little flattened but the corners looked good, no sticky bolt, and a very light extractor mark. bottom line is the case's did not look like there was to much pressure.

2nd question. he chronographed his gun at 2794 and 2809. I thought it couldnt be, but today it validated on exball at 2808.

He and I wanted to hear your thoughts. There are no case pressure issues evident, but should we look for something else? any hidden issues we should look for, and lastly, anyone else getting this kind of velocities with this configuration of bullet, powder, caliber and barrel length?

This is nearly identical to my edge with the same load.

thanks, and have great day.

 

[Long Time Long Ranger]

No surprise at all. The 338-300 ultramag and the 338 ultramag are virtually the same thing. That is why most people working with the 338-300 ultramag went to the 338 ultramag in 2001 when it came out. Same accuracy and virtually the same velocity and one is standard off the shelf easy to load products. Makes it a simple choice.

 

[royinidaho]

Ditto on the no surprise at all comment.

I shoot a 338 RUM Rem 700 Sporter w/300 SMKs @2734 MV w/ 101 gr US-869. Could go more but am pretty tired of messing with cases. This load is very comfortable load and easy on brass.

Much depends the difference in barrels. Some chambers and barrels simple shoot faster than others.

 

[lamiglas]

These are the types of answers we wanted to hear! thanks for taking the time to respond.


It sounds like with the same 90 grains of powder these two should shoot close to the same, but i am suprised the 4" of barrel difference doesnt cost the RUM to shoot a little slower.

if anyone else has anything to add, please do so.

have a good day

 

[highridge1]

I agree the 338 RUM is close in performance. A example of a difference though is my 338 edge will shoot 96 gr of H1000 without pressure signs and run 2910 fps. Not alot of difference but has a little performance edge on the standar 338 rum. I have heard of a few guys reaching the high 2900's and 3000 fps with retumbo and the edge.

 

[mike33]

What is your brrel length of your edge? My edge should show up in a week or so.
Mike

 

[pitbull320]

I had to do this for my self I just happen to have both the edge and the rum I loaded up some test rounds and with 94gr of retumbo in my edge with 300 smk and with a 28" tube i got 2850 and out of the rum same load it was 2710 with a 26" tube after this I up the loads to 98gr and at this I got 2904 out of the edge and the rum was 2794 but the second round out split the case in half so I stopped there and just so there's no talk of case faller these where new cases so I would be very careful in load these to round to hot

 

[Topshot]

The .338 RUM has a slightly smaller case capacity than a .338Edge depending on throat length and seating length.

Smaller case with same powder charge = higher pressure.

If the .338 RUM is running at higher pressure it could be why it gave a similar velocity even though the barrel length was shorter.

 

[Long Time Long Ranger]

lamiglas, I just went back and found your question hidden in there. I just scanned over it the first time. 90 grains of h-1000 with the 300 smk is on the hot side for the 338 rum. Every gun is different so if it shoots it shoots. Mine is a rem 700 and it will shoot that load but I am off the lands with the seating depth so it will feed through the action. Your 338-300 ultramag should go a few grains hotter than 90. Key to it is where you get your accuracy. Retumbo does well in my 338-300's also.

When I did all the tests with both of these back in 2001 when the 338 rum came out it just depended on the individual barrel as to velocity difference. Apples to apples you get a fast barrel in one and a slow barrel in the other it changes things dramatically. At my range I had the opportunity to chrono many rifles. If I averaged out all the data with best accuracy loads in each there is probably 50-75 fps difference on average but with barrels many times you don't get average. After shooting them head to head and getting the data I didn't see a need to continue building the 338-300's any more after the 338 rum came out. They were so close and the 338 rum was over the counter products so I didn't see the advantages of the 338-300 worth the disadvantages of doing it over the 338 rum. This was a tough decision because I had spent all that time designing the best 338-300 ultramag chamber and throat since remington released the specs on the 300 ultramag back in the 90's. I also had done that same work on the 7mm-300 rum and 358-300 rum. I still have two of each of those original rifles I kept for myself. I really like the 358 version but it just never took off because of no high bc quality bullets in 358. It is a killing machine though out to 800 yards or so. If velocity was important for a guy that was shooting over 1000 yards then it made more sense to step up a couple hundred fps to the 338-378 wby and the improved versions in a custom rifle instead of the slight increase the 338-300 ultra gives you over the 338 rum. Or improve the 338 lapua case and go that route which gives an extra 100+ fps over the 338-300 ultra.

The design I settled on with the 338-300 ultra was on average the fastest considering the loads and velocities I see posted on the internet. Most guys could get 2900 fps with the 300 smk with my design. From what I read on here the average seems to be 2750-2850 fps with the 338-300. All of them I did were specialized for long range elk hunting. I don't know how many guys are still on the site using them since I quit doing them about ten years ago. Back then there were several guys from Colorado reporting long range accuracy and elk kills with those first rifles. The 338-300 ultramag is a great cartridge but so is the 338 rum. Just not really enough seperation there to make one noticably better than the other. Like I say a guy would need to step up to the improved lapua case or 378 case to gain enough seperation to make it a worthwhile move over the 338 rum. Each guy decides for himself which is worthwhile, that is why there are thousands of different variations of cartridges out there.

Sniper2 is still on here. He might could report the velocities all the guys down his way are getting with those first rifles. I think all of those were 28-30 inch barrels.

 

[lamiglas]

A ton of great information. Thank you to all that have replied. I am using 90 grains of h-1000 mostly because I started there and I have no motivation to fix what isnt broke. with my 30 inch barrel, i validated at 2808 and I am sure i could gain some velocity but I am sincerley content at this point.

Brad is going to load up again here soon and will look for signs of loose primer pocket etc, but so far it really does appear the load is not generating to much pressure for his rifle.

by the way, he is using a hornady overall case guage and loading 10 thousands off the lands.


I will re-read all posts again when i get home, and thanks again, everyone here gains from your knowlegde.