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

[Bang4theBuck]

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?

 

[DoneNOut]

My answer is to go slower powder. With that comes the benefit of more powder fill capacity to bring down ES/SD.

 

[memtb]

You're doing a good deed for the gentleman! The "screaming " velocity is unnecessary for smaller big game…..especially if not doing "looong" range shooting!

I don't have any suggestions for loads…..but you get a from me for your efforts! memtb

 

[DoneNOut]

You're doing a good deed for the gentleman! The "screaming " velocity is unnecessary for smaller big game…..especially if not doing "looong" range shooting!

I don't have any suggestions for loads…..but you get a from me for your efforts! memtb

I do love me some, "Speed Kills" but heck, the guy already got that with a 270 WBY Mag and inherent speed bracket. LOL

 

[willfrye027]

Below book can be pretty dangerous.

Could also try a lighter hammer projectile to reduce felt recoil.

I load a 110gr hammer hunter for my wife's rifle down at 2850fps. In my own rifle it's moving 3200fps. Big difference on felt recoil for sure.

 

[Bang4theBuck]

Below book can be pretty dangerous.

Could also try a lighter hammer projectile to reduce felt recoil.

I load a 110gr hammer hunter for my wife's rifle down at 2850fps. In my own rifle it's moving 3200fps. Big difference on felt recoil for sure.

Which cartridge are you talking about here? If I could get the 110 down to 2850, I would be a happy camper. Which cartridge and which powder (and aprox charge, if you are comfortable with that publicly, or via PM)

 

[Dmagna]

Go with a smaller bullet. That will take a lot of recoil out of it. A 90gr hammer will do the job just fine

 

[Calvin45]

It pains me to think about tuning down a weatherby haha.

That being said it should be doable BUT as the previous poster states going below book starting loads in large cases, especially if they're overbore too (an arbitrary word that simply means "of a higher case to bore ratio than is typical" as I'm using it here).

The .270 bee isn't in the same category as the .257 wby or 6.5-300, to say nothing of rounds like the 7mm rum and .30-378 wby. But this rule still applies. I wouldn't go below book.

Of course, in a way you're flying blind regardless as hammer load data is entirely user generated, not pressure tested, and practices vary wildly among individual handloaders.

one option would be to use an inappropriately slow burning powder with this combo so that there's no danger regarding secondary detonation as you can still have case fill in the vicinity of 100 percent. It'll burn dirty, you'll have sooty necks, but if you want a perfectly safe lower velocity load this will get you there and probably with great accuracy and consistency HOWEVER….she's still gonna kick more than she needs to then. Remembering that propellant volume contributes a fair bit to overall recoil, it's not at all just about projectile mass and muzzle velocity. So if the whole point of this power reduction is recoil reduction that's kind of suboptimal as a solution. I've done this with .300 win mag but not to reduce recoil but rather to use up existing supplies and go shooting. H50bmg is entirely too slow for the .300 Winnie, but using a 208 hpbt crushing 80 ish grains of powder into the case we had a 1 ragged hole accurate group with very low sd numbers…but an average velocity of somewhere between 2600-2700 fps, well short of what is realized with more appropriate powders. And the thing is, to me subjectively, this load didn't really kick any less than those faster moving rounds with the same bullet weight did.

So while it has its challenges I think you do want a faster burning powder at a low but safe and verified charge weight. What id recommend, what I would do if I were in your shoes anyways and maybe I'm wrong, is if using a load that's a good way below max pressure and case capacity, be sure to crimp this bullet HARD. My preference for crimping is the LEE FCD die, best there is for this job regardless of price, and wouldn't ya know that it's delightfully inexpensive too! Two reasons, safety and consistency. First off, I've already mentioned the danger of hangfires and secondary detonations in overbore magnums with lighter charges…and even more than some other magnums this goes for weatherbys with their massive free bore. Add to that the fact that the hammer bullets you plan to use have very low bearing surface and initial engraving pressure and you've got reasons to CRIMP THAT ROUND!!! I predict
That with this kind of load crimping should avail itself to tighter sd and es numbers as well, which isn't always a big deal but certainly NEVER hurts anything either.

Now that's if you must commit this ballistic sin!!!

What I would ACTUALLY do if recoil is the problem is just put a brake on the beast and LET ER' RIP!!!!! Weatherby cartridges and hammer bullets both just wanna go fast!

 

[Bang4theBuck]

It pains me to think about tuning down a weatherby haha.

That being said it should be doable BUT as the previous poster states going below book starting loads in large cases, especially if they're overbore too (an arbitrary word that simply means "of a higher case to bore ratio than is typical" as I'm using it here).

The .270 bee isn't in the same category as the .257 wby or 6.5-300, to say nothing of rounds like the 7mm rum and .30-378 wby. But this rule still applies. I wouldn't go below book.

Of course, in a way you're flying blind regardless as hammer load data is entirely user generated, not pressure tested, and practices vary wildly among individual handloaders.

one option would be to use an inappropriately slow burning powder with this combo so that there's no danger regarding secondary detonation as you can still have case fill in the vicinity of 100 percent. It'll burn dirty, you'll have sooty necks, but if you want a perfectly safe lower velocity load this will get you there and probably with great accuracy and consistency HOWEVER….she's still gonna kick more than she needs to then. Remembering that propellant volume contributes a fair bit to overall recoil, it's not at all just about projectile mass and muzzle velocity. So if the whole point of this power reduction is recoil reduction that's kind of suboptimal as a solution. I've done this with .300 win mag but not to reduce recoil but rather to use up existing supplies and go shooting. H50bmg is entirely too slow for the .300 Winnie, but using a 208 hpbt crushing 80 ish grains of powder into the case we had a 1 ragged hole accurate group with very low sd numbers…but an average velocity of somewhere between 2600-2700 fps, well short of what is realized with more appropriate powders. And the thing is, to me subjectively, this load didn't really kick any less than those faster moving rounds with the same bullet weight did.

So while it has its challenges I think you do want a faster burning powder at a low but safe and verified charge weight. What id recommend, what I would do if I were in your shoes anyways and maybe I'm wrong, is if using a load that's a good way below max pressure and case capacity, be sure to crimp this bullet HARD. My preference for crimping is the LEE FCD die, best there is for this job regardless of price, and wouldn't ya know that it's delightfully inexpensive too! Two reasons, safety and consistency. First off, I've already mentioned the danger of hangfires and secondary detonations in overbore magnums with lighter charges…and even more than some other magnums this goes for weatherbys with their massive free bore. Add to that the fact that the hammer bullets you plan to use have very low bearing surface and initial engraving pressure and you've got reasons to CRIMP THAT ROUND!!! I predict
That with this kind of load crimping should avail itself to tighter sd and es numbers as well, which isn't always a big deal but certainly NEVER hurts anything either.

Now that's if you must commit this ballistic sin!!!

What I would ACTUALLY do if recoil is the problem is just put a brake on the beast and LET ER' RIP!!!!! Weatherby cartridges and hammer bullets both just wanna go fast!

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.

 

[Bang4theBuck]

Here is another question:
The boom said that I would get near 3000 fps with a 130 grain bullet with the min charge of H1000. So, if I am getting 3420 out of the Hammer 124 gr. Even knowing that the Hammers are faster than typical, it would seem, potentially like I could reduce that charge weight a bit until I get something closer to the book velocity. So, said another way:
76 grains (starting load) = 3420
Assume hammers account for 100 fps of the increased velocity = 3320
Assume 124 versus book 130 accounts for 50 fps of the increase= 3270 fps.
It would seem that I could reduce the charge a bit below min to get down to the book stated 3000.
No comments about funky math! Is anyone tracking where I'm coming from?

 

[xsn10s]

I looked at Nosler's and Hodgdon's load data for bullets near that weight class. To slow down those 130's to near 270 Win loads I think I'd try H4831 or maybe IMR 4350.

 

[willfrye027]

Which cartridge are you talking about here? If I could get the 110 down to 2850, I would be a happy camper. Which cartridge and which powder (and aprox charge, if you are comfortable with that publicly, or via PM)

sorry, completely different cartridge. Just making a point.

I'd just pick a lighter bullet and go for book minimum loads.

You can google "recoil calculator" to get an idea of how a 110gr at 3000 will feel vs a 124 at 2900, etc

 

[scpaul]

No matter which powder you choose I wouldn't go below 50% density. I'd fill the rest of the case with dacron or tissue paper to keep the powder at the base of the case and close to the primer for proper ignition.
It was suggested years ago that the majority of the powder was at the front of the cartridge and when the powder at the base ignited it caused a secondary explosion when the forward powder ignited. This was just a theory at the time. I don't know if they ever proved what was causing the secondary explosion that was causing the damage.

 

[asd9055]

My personal experience with WBY is that they do like the upper end of powder, however, I do have one rifle that is tuned "one node" below that. It takes work.

You had some good suggestions here to try.

This is what I would do: If you have a chrono, shoot 5-10 round, same everything and chrono. Use data in GRT OBT and it will give you suggestions for the various nodes. Get the load for the slowest speed, but still above "Book min" and play with that.

OBT is Obtimum Barrel Time
GRT is Gordons Reloading Tool

Note: IF you are using Hammers, both GRT and QL have difficulty modelling them. At least is what people say, I have never tried.