Slowing down a hot cartridge (don't hate on me for asking)

[cb186]

Hodgdons reloading data shows Accurate 4350 to be a real good option for reasonably mild loads. Its also readily available.

 

[BrettB]

Good morning,

I debated even posting this request, but I know know better forum to ask this legit question. Here is the quick story:

I have a new friend that I met at the range. He is an older gentlemen that has had this WBY Mark V in 270 WBY Mag. He shelved it a few years back because he couldn't get it to shoot well enough to be dependable. There is sentimental value in this rifle not to mention it is a Roy Mark V, so any self-respecting rifleman should want to jump at the opportunity to get this thing shooting. Firs thing I did before investing any time was to scope the bore. It was chucked full of powder fouling and heavy copper fouling. So, I spent 4 hours stripping all that out of it, to find that it looks to be a relatively low mileage rig. I then clearanced the barrel from the stock, to give the barrel a chance to float. Then I order up some 124 grain hammer bullets, and researched a good load.
This friend of mine as no intentions in the near future of using this rifle on anything larger than a whitetail deer, so I wasn't after lightening bolt velocity (I know here is where the hating might start). I researched two different approaches, with the intent of developing a slower, more mild recoiling load, and a higher velocity load. I stayed near the book minimum charge of H1000, and still got really snappy recoil, and over 3450fps. I was shooting for something down closer to 3000 FPS, which the book said I could get. The accuracy was 5x better than he was getting previously, so we called it a success on that front. However, I am still wanting to further reduce that load, and make it more comfortable to shoot.
I have never messed around with charges below the starting charge. Is this advisable/safe to do, and in this exact instance, how low can I go without getting into the weeds?
I have other powders available as well, but H1000 according to the Hodgdon website was supposed to be one of the lessor performing powders in this cartridge.

Suggestions on a lessor velocity load for this cartridge to reduce recoil for the guy?

I had one of those and it was really finicky, I switched to large rifle primers and the groups immediately tightened.

 

[BrettB]

I had one, it was real finicky, I ended up switching to large rifle primers and my groups immediately tightened.

 

[Lenny Foffa]

Hi I also own a 270 Weatherby Mag ,and I have shot reduced loads with the 150 Grn ABLR for weekly range sessions at 300 yards, in prep for the LR school I was going to take that rifle to. Ex; When I put the new scope and rings on, I went to, the range and started sighting in at 50 yards and then 100 Yards, I used 67.5 Grns. of 4831 SC, and 67.7 Grns. of 4831 SC for fun target shooting , before I went to 67.9 Grns which was the load I took to school. With a full load 69.0 H 4831SC for 3068 FPS if I wanted too use that. I wanted an even 3000 fps for the JBM ballistic app. I am now using a Reduced load for my 300 Weatherby Mag. New Leupold scope and new Kenton Elevation turret,\ on it. I'm using 74.0 Grns of H 4831SC with Horn 178 Grn A max bullets. Easy Load to sight in with. I'm doing that again today. When I go back next week I Will increase the load to 74.6 Grns . and shoot some more. So in summary ,I have no issue in playing with reduced loads, and saving targets to determine accuracy as I build up to serious hunting loads. I always would prefer a more precise load, say 90 percent , as opposed to the Full Throttle 100 Percent Plus load. Just my humble opinion This rifle will only be used for Penn Elk Hunting , if and when ever I am selected by the lottery . The Rifle/ Load/ Scope set up will be ready when ever that time comes.

 

[Calvin45]

I wanted to provide an update on this unique project. A fine gentlemen from Hodgdon was on the phone with me for over a half hour on Wednesday talking through the possibilities. His strongest suggestion was to use Trailboss and to use the 'load it to the base of the bullet' method for establishing max load, then back off as much as 30% from there, If I wanted to. This worked out fairly well actually. It printed the 124 Hammers at around 1960 fps, with very very mild recoil, ESs around 20-30 FPS and 1- 1.5 MOA accuracy.

The only bad part is if I want to keep the impact velocity above 1800 fps, this would make the max range ~75 or 80 yds. But we we are definately knocking on the door of something great, I think.

So, I ordered the 90 grain Hammers and intend to try them with both the trailboss (hoping to get 2300 fps) and with a starting charge of H1000 (hoping to get a full power load ~3000 FPS, with low recoil). Hoping for big things here! I'll keep you posted.

Fascinating. You've turned a .270 wby into a 6.8 spc!

I don't know how I feel about this but am impressed that it worked

 

[308plinkerVT]

The old Lee manual puts H870 as your likely choice to stay with this weight, at around 2860ish for velocity (not listed directly if anyone else goes to review me). I would also agree going with a lighter projectile would be best, Lee starts at 90gr on this with several powder choices, less forward almost always means less backwards (;
Added: juts noted the trailboss info - awesome that it works in this cartridge scenario.

 

[Bob Wright]

I appreciate this feedback. The slowest powders I have on hand are:
RL 26
IMR 7828 SSC
H1000

A muzzle brake is what I would do, but this friend doesn't want to thread the barrel, so that is why I am working woth loading solutions.

Buy a Witt Machine clamp on break. It's real easy and fast delivery from them.
My 30-06 with a light weight spaghetti barrel shoots way better now and the vertical stringing is no longer there. It's not "pretty" like other breaks but it is ported on top for muzzle rise reduction and the side ports work very well to eliminate pain.
It is removable with just an Allen wrench.
Using a lighter weight copper mono will be a game killer and less recoil.

 

[Bob Wright]

One more thing, less than book minimum could cause flash over powder burn and its dangerous.

 

[Buttermilk]

If you are wanting to tame the recoil, Hodgdon has a pdf on their website (takes some digging to find it) that says if you have data for that cartridge showing H4895 as a powder choice, you can load to 60% of the max charge for reduced recoil. I've done just that with a 30-06 for a small statured 12 yr old boy who wanted to deer hunt.


I've not looked to see if H4895 is listed for that cartridge.

https://imrpowder.com/wp-content/uploads/2016/11/h4895-reduced-rifle-loads.pdf

https://www.ballisticstudies.com/site/ballisticstudies/files/Hodgdon%20H4895%20reduced%20load%20data.pdf

 

[marksman1941]

It seems like you're on track for the powder you need to use. An accuracy note that may or may not be helpful.

My grandpa has an old weatherby in .270 win, and while trying to accurize a bit he hogged out barrel channel to free float it. Groups opened up tremendously upon doing so. He called weatherby (mind you this was 35-40 years ago) and they explained that those rifles had a post in the stock that created a pressure point on the barrel and was necessary for accuracy. They (weatherby) suggested he take a stack of mailing labels and start layering them inside the stock about 2/3 up the barrel channel until they made contact with the barrel. Then add one label, shoot a group, add another label, shoot another group, until the vertical stringing he was seeing disappeared. At that point use bedding compound to build up a point the same height as the label stack and you're good to go. It worked, weird as it sounds.
I only mention this in the event you have a hard time finding accuracy once you've settled in a general load. There may be something to look into in the stock if you're chasing 1moa

 

[RichCoyle]

Bang,

When I wanted to do that with a 7-.300 Wea I called Sierra. The tech told me to use IMR3031 and go with the lowest load you could find in the book with a 120 grain bullet. Then reduce it until you can see a little powder left in the barrel. Eventually I just went with pistol powder with some fiber fill holding the powder against the primer. As the young man became accustomed to the rifle, I switched to the 3031. Eventually he was firing 7X57 power loads without ever knowing I changed anything ending with 175 grainers.

 

[JAYgs8163]

Buy a Witt Machine clamp on break. It's real easy and fast delivery from them.
My 30-06 with a light weight spaghetti barrel shoots way better now and the vertical stringing is no longer there. It's not "pretty" like other breaks but it is ported on top for muzzle rise reduction and the side ports work very well to eliminate pain.
It is removable with just an Allen wrench.
Using a lighter weight copper mono will be a game killer and less recoil.

Best advice here along with just a low book load. Don't have to worry then.

 

[orifdoc]

Limbsaver recoil pad. I unashamedly used one on my .416 Rigby in Africa. Might be a little tight if he has a small build or short arms.

 

[Big Guy]

I appreciate this feedback. The slowest powders I have on hand are:
RL 26
IMR 7828 SSC
H1000

A muzzle brake is what I would do, but this friend doesn't want to thread the barrel, so that is why I am working woth loading solutions.

ii have a WITT Machine muzzle brake on a 330 Dakota i works,,, it is a slip on, if you do your part with good measurements it fit prefect, you can remove it and leave no marks, i used lock tite with there lock screws...WITT MACHINE and TOOL 940 461 8805 nice people to work with....Leon