I have a (new) heym 88b 470 with 24 inch barrels that I am working up loads for and I also have a new Chrony Beta- that I am using to do this and I am abit paranoid about these things as this is my first time reloading for the Big NE's and my first double, so I wanted to consult the accumulated wisdom here. Is there an absolute maximum amount of R15 I should stick to with the 470NE?

My load right now is with full length resized once fired norma brass,500 gr woodleiegh softs, 93grains of R15, and a kynoch foam wad.I had to use winchester magnum primers because the federal 215's are impossible for me to find in ontario. I decided not to crimp-My brass comes out of the RCBS dies (expander removed) with a Neck ID of .467" (.007 undersize) and seems to grip damn tight.

This is chronoing about 2080fps (I have checked the chrony with factory norma 500grain solids and they are at about 2175-2200 fps).

I started at 86 grains (1920 fps) and worked my way up from there. At 93 grains my left barrel still shoots 2" to the left- The right barrel is darn close to where it should be (this is at 30 yards). I am sure if I keep going that the left barrel is going to come in towards poa and velocity will equal the norma loads.- I figure at about 96 or 97 grains.


I am however starting to get abit nervous as I see most loads are listed under 90 grains- and on steves reloading pages 90 grains is listed at the max. If my chrony says 2080 and the left barrel still wants to move towards the POA should I keep going up till 96 grains or am I creating a questionable amount of pressure here?

I am wondering if the difference could be in the primers as most use federal?
How much difference would it make in velocity if I started to crimp?
FYI the gun was regulated with federal 500 grain trophy bonded at the factory

(PS-my hats off to you guys that are shooting stuff bigger that .470- Holy hell these things KICK- I'm damn sure my biggest gun ever is going to be a .470. Makes it real nice to go back to the .375 after half a dozen sighting in shots with this thing.)
Thanks for looking
Dan

quote:

Originally posted by notlim:
At 93 grains my left barrel still shoots 2" to the left- The right barrel is darn close to where it should be (this is at 30 yards). I am sure if I keep going that the left barrel is going to come in towards poa and velocity will equal the norma loads.- I figure at about 96 or 97 grains.Dan

I don't believe you're as far away as you think you are. A 2" spread may sound like a lot, but it's really not in a big double. I would say 1-1.5" is good enough. Also, don't be concerned about the windage. You can adjust that by simply drifting the rear sight.

Before you go any farther, however, I would reccomend that you shoot those loads at 50 yds and also at 100. Those distances are important too, and will tell you more about the load than shooting only at 30-yards will.

Plan B would be to try another powder.

That appears to be a really slow lot of RL15 you are using. I use dacron for my filler so I'm not sure how much that would matter just be real careful if you end up needing to buy more powder from a different lot.

I heard there was quite alot of variation possible between lots, so bought a 10 pound keg.
My shoulder will be mighty sore before I run out of it.

So you guys both think I probably am not at a high pressure? Should I keep going up to 96 grains?

The powder charge isn't as important as the velocity is. If you're at 2080 now, I would probably go up to 2150 and stop there (Federal is running in that range with RL 15 and below MAP.)

Remember that it's much cooler in Ontario in April than it will be in July in Zimbabwe. That will affect your velocity and regulation too.

You should back off a few grains this summer and check your velocities and regulation again.

WOW ... 93 grains of RL-15 to get 2080?

Either 1) the difference between WLRMs and FED 215s is very significant, 2) you're using cases that are quite thin and thus have a lot more available volume that there is in the BeLL cases I use, or 3) your lot of RL-15 is way slower than any I've ever seen.

Have you checked your chronograph with a sample of known velocity ammo?

notlim,
I also have started shooting a new Heym 470,your loads sound too hot to me,mine is regulating very well with 83 grains or so,I would not risk overloading your gun,try a different brand of powder first,imr 4831 e.t.c I would first determine whether you have a slow batch of powder or your gun just needs more powder,I would also put back the expander,too much neck tension will increase your pressures as well,for now until you are sure of where you are at with your loads,best of luck

Bill,
did you chrono your 83 grain loads? Do you know what kind of brass you used and what it weighed?
Federal 215's?


I chronoed some of the Norma factory loads 500 grain woodleigh solids and they were at 2175 and 2190
with the same chrony so I figured that it must be reading pretty close. And I figured that it showed my barrels aren't particularily slow.

Maybe the Norma loads are very hot?

Temperature yesterday was about 45 or 50 degrees.

I was thinking that the primers might also be the cause but as I don't have access to any federals I am stuck with them.

Regarding the neck pressure- if I put the expander back in and loosen the neck- won't I need even more powder due to the lower pressure generated there?-

I figured it would be tough to get a consensus- BUT if my velocity is low and I am not yet at regulation-it would seem to me that my primer/powder/case combination is just not producing enough pressure?

I have found one other poster who said he had to use 96 grains of R15 to get to 2150fps. What else could I possibly check/change- I checked the chrono with the norma factory loads- calibrated my scale, and weighed every charge.

Are you guys all crimping your loads?

check your pm's

I may have missed it in your previous posts, but you are using a Dacron polifil filler on your RL-15 loads? If not you need to. RL-15 is a position sensitive powder. As long as you keep against the Federal 215 primers, you will get very consistant velocities.

If you have any factory ammo that the rifle was regualted for, I would shoot that across the Chrony to get a benchmark and to see how it shoots in your rifle.

Hi Rusty,
I'm using the kynoch #2 foam wads as a filler.

I can't find any federal .470 here in ontario to use as a benchmark- On my research here and on Nitroexpress it seems that the federal is(or was) pretty inconsistant so it might not help all that much anyways.

I just wanted to add I have had what I consider to be large variations in burn rates with RL15, but nothing as slow as you are seeing. Might be the primers as others have mentioned.....

Anyone ever try IMR4831 instead of RL15?

I use H4831 SC. Started out with 108 Grains. Kept getting Muzzel Flash. It went away at 110 to 112 grains. I have used up to 116 grains with no signs of pressure. I loaded some today at 113.0 grains I use Swift 500 grain A-Frames and Barnes 500 grain flat nose solids. The Rifle is a Krieghoff Double. The Brass is Federal Nickel Plated. Even at 116.0 grains the emptys drop out when I tilt the Barrels up. The Primers are not flattened. I know this is above what the Books recommend, but it works.

One of the many things I have learned from members of this board is that pressure signs are very different when loading for the older nitro express rounds. The basic thought is that you can be over pressure and potentially damage a rifle with loads that show none of the normal indications. Pressure limits sometimes occur well before flat primers and sticky cases become visible. I am not saying that Larry's loads are dangerous however I think we should all proceed with care when loading for a double rifle. What works in one rifle may cause problems in another. The same can be said with lot to lot powder variations. Pushing the limits can cause expensive and potentially dangerous problems.

I agree completly with Roscoe. My loads were worked up 1 grain at a time in my Rifle. I would not start out with them in another Rifle.

Since your Chrony seems to be OK with factory loads, I suspect the results you are seeing are due to brass and primers.

My current lot of Rel 15 regulates with 88 grains Rel 15 using Bell Brass and Fed 215 primers, works out to be 2180 FPS in my Krieghoff. While powder lots will differ, this appears to be quite a lot.

Any chance you can order some Fed primers somewhere? Any one here try using CCI Mag primers with their double reloads?

One last thought, what is water volume of your resized brass?

I have used them as well as Federal and Winchester and have not noticed any difference between them.

I checked water volume and for resized brass with water filled convex it is 150 grains, once fired brass not resized is 153 grains of convex water capacity. What is typical with the bell or jamieson brass?

Federal primers are unobtainable within ontario as far as I can tell at the present moment- I've personally been to every gun store within a 300 mile radius of my house and the only one anyone has in stock so far is winchester magnums.

I am really wondering if my velocity is low, and my gun wants more powder in order to finish regulation- isn't my pressure correspondingly low?

How can I have low velocity and high pressure? Isn't it the pressure that creates the velocity? (Probably a pretty simplistic question but I'm a real simple guy )

My felt recoil is dramatically less than the norma factory loads I have, as is the velocity over the chronograph- doesn't that mean I am developing less pressure than the factory stuff?

Can you get any H4831 or H4831SC or IMR4831?
Also Crimp your loads. Having to use Filler adds a varible to the equation. A slight Crimp also helps to uniform the Burn. If your getting Muzzel Flash then start working up 1 grain at a time.

I just picked up some h4831sc today (got hosed good on it too: $47.99/lb @ the local gun emporium) , I checked the hodgdon website and they list 114 grains as the starting load- 119gr as the max load. This seems to be quite alot higher than everyone's experiences here- I think I will start at 107 grs and see how it works.

I bought 10lbs of r15 anticipating using it in my 470- guess I have a lifetime supply for my .375 if the 4831 works better/more normal.

I think you will like the H4831SC. I just pulled a Bullet from a Factory Federal 500 gr TBBC and weighed the powder. It weighed 89.8 grs. Looks like some kind of Short Cut Powder.

Not sure which Bullet you are loading, but be sure to use a slight Crimp.

quote:

Not sure which Bullet you are loading, but be sure to use a slight Crimp.

YUP

I believe Federal uses Rel 15. They do not use a filler because they use a hot #216 primer not available to us.

With H4831SC & 215 primers my Heym was shooting about 2160 FPS with 107 grains....

quote:

Originally posted by notlim:
I am really wondering if my velocity is low, and my gun wants more powder in order to finish regulation- isn't my pressure correspondingly low?

How can I have low velocity and high pressure? Isn't it the pressure that creates the velocity? (Probably a pretty simplistic question but I'm a real simple guy )

My felt recoil is dramatically less than the norma factory loads I have, as is the velocity over the chronograph- doesn't that mean I am developing less pressure than the factory stuff?

No, different velocity from different powders does not nessecarily or reliably indicate that the slower one is producing less pressure.

No, different felt recoil from loads with different powders (and velocities) does not nessecarily or reliably indicate that the load generating less felt recoil is producing less pressure.

JPK

The thing that always causes the actual amount of recoil is the weight, speed, of the bullet, and the weight of the rifle. For every action there is a predictable reaction in the opposite direction!

The amount of "FELT" recoil can be moderated, or exacerbated by fit, softening recoil pads, and the weight of the shooter. "FELT" recoil has little to do with the actual amount of recoil force, which is dictated by bullet weight, speed of the bullet, and weight of the rifle.

Contrary to popular belief, a light person can handle recoil with less pain that a heavy person. The light person is moved by the recoil, (rolls with the punch) far more readily than a heavy person who absorbs more of the recoil into his body.