Reloader-17 and 4350

[Mustang]

I've begun experimenting with Reloader-17 in 7.5 x 55. Yesterday I tried several loads with Nosler Custom Competition 175's (practically a clone of the 175 SMK.) with decent results. I used charges of 48.5, 48.8 and 49.2 grains of RE-17, with my best results being with the 49.2 gr load. I got no obvious signs of excess pressure with the 49.2 load, but am somewhat concerned by data in the reloading manuals.

I've found no published data for reloader-17 reloading in the 7.5 x 55 cartridge. A call to Alliant confirmed that they had no such data, but advice that RE-17 had a similar burn rate to IMR 4350. I've checked my reloading manuals for IMR 4350 and found that 49.2 grains is over the limit in both the Sierra and Hornady manuals for 175 grain bullets and 4350 powder.

My questions...

-Is anyone using a load of reloader-17, either at 49.2 grs or above, with 175 grain bullets in 7.5 x 55 and if so, have you seen any signs of excess pressure?
-Is the burn rate of RE-17 different enough from 4350 that I shouldn't obsess about this load exceeding the max for 4350?
-Anyone have any thoughts on this load?

Thanks.

[knucklehead0202]

one of my customers was a swiss rifle nut and highly recommended the use of RL17 for the 7.5x55. didn't recommend a load but you should be fine. I haven't loaded any of my 7.5x55 yet but have begun using it in my 7.7 jap. the results are pretty impressive, really want to chrono and see what it does. in certain chamberings, reloder 17 yields much improved velocities and good accuracy, it's just a matter of figuring out what chamberings and I'm sure creative people will discover them. sounds like your load is good and I'd stick with it unless you get any indication it's a problem.

[Mustang]

Thanks, knuckle.

It is amazing how much difference a few .1's of a grain of powder can make.

I used this target to test the loads.

[

I set the sights of the K31 to 200 and fired the upper left hand (8") target with 4 rounds of 48.5 grains of RE-17 and was aiming with a 6 o'clock hold on the small (5.5") just beneath it. I then fired 5 rounds of 48.8 grains of RE-17 at the right hand 8" target, again with a 6 o'clock hold on the 5.5" target just below it.

I then moved the sights on the K31 to "100" and fired 4 rounds of 49.2 Re-17 with a 6 o'clock hold on the 5.5" target at the bottom left, getting a group just to the left of my aim point. That was the best group of the test.

[1-M-42]

Steve. you are almost 2.5 grains over my max load with Re-17. I think Latigo had some load data posted, either here or on the Swiss Rifle board, but his bullets and barrels were all Hbn treated (I think thats what it is) and he had less pressure. I found that I started to have case head separation at 48 grains or so with flattened primers. I'll check my notes when I get home tonight. You want them around 2600 fps to match the GP-11

[Mustang]

Thanks, Bob. Was that in your K31 or 1911 rifles?

[1-M-42]

K31, I don't have my book with me but I think I'm loading 47.5 or so on a max load. Less is my standard

[Latigo]

I forgot about this, but I'll check the original data logs in the armoury. I know we have the early data before hBN logged in.
Later.

[knucklehead0202]

think I was going to start at 47.5. once I make a little money I'm going to order a bunch of bullets, kinda low on .308 stuff and only have 150gr right now.

[kouye]

I never had much luck with RE-17 behind Berger VLD 175's. But I have GREAT luck with N140 or Varget behind Lapua Scenar 155's.

Edit: I should add that I also tried I4350 with about the same result as with RE-17 behind the Berger's.

[Latigo]

Being nearly a dead match for the GP11 projectile, we use Berger 175 VLD's exclusively. Identical seat depths put the ogive right at the lands where it belongs.
RE17 also seems to be a dead match for the original powder, and not strange since it comes from the same factory in Switzerland making that powder since 1911. The main difference would most likely (maybe) be the coagulents. Under a scope it looks the same, weighs out the same by 100 logs and even smells the same.

This is ABSOLUTELY NOT a recommendation of any kind for your own reloads or your rifle. This is what we did and how we did it before hBN and using ICP's exclusively.

The brass is and for the past 10 years has been the beefy Swiss RUAG National Match brass. Norma brass will not act the same. The cases are FLS sized on a Forster with the primers being seated on a Forster. If you know the Forster press, you'll understand why this was important to us. TTL is critical and is always done on a Wilson. Projectile seating is done with a Redding Micrometer die and repeatable neck tension is also critical. (For us)

The RE17 data was worked up from 46 grains and ended at 50.1gr with an un-treated barrel. This ended as an accuracy load for us. It may or may not for you. This is a relatively hot load!

The switch to ICP's meant an immediate drop in velocity so we worked back up to 52.1gr of RE17 to achieve the same velocity as with the untreated bores and non-ICPs. The barrels are all hBN slurry sealed now.

There is an inherent danger here if you have rifles with untreated bores in the same rack as rifles with treated bores, and that's exactly why every bore in any and all calibers and rifles in our armoury here are hBN slurry sealed. There's no chance of inadvertently using an ICP with a 52.1gr charge in a rifle with an untreated (read higher velocity) barrel.

As you approach the RE17 47.5gr charges you must chronograph those shots.
Use GP11 cartridges as a MV control base and chronograph them. If you're using a 175gr projectile you'll want to emulate the MV of the GP11 with your own reloads. From there, follow the groups as they open or tighten. They can close, open and close again up the scale. Consider 5 round groups as your minimum. Once you're satisfied with that, go to 10 round groups to make it prove itself.
Record/chrono every shot until you find that golden recipe for your particular rifle. You may end up with a completely different and lower charge that works for you.

Just for fun, break a GP11 cartridge and weigh the charge and projectile weight, then run a complete spec check on the case. It's informative and educational.

Good shooting and reload safely and logically. Record everything.
If you don't have a Chronograph, this will all be a roll of the dice, and not a very safe one.

[ducky_0811]

I use 4350 with both SMK and Graf seconds in 175gr with good results, the Sierra manuals "accuracy load" proved right for my rifle, I've used 4064 as well with slightly less equal results

[Latigo]

Ok, so I've seen this same post around the C&R forums, and I have a question.

When you're near the top end on any published data and you've heard that the best performance point is an unknown above the published data, why are you not using a chronometer for the sake of your face, eyes and hands?

They're not that expensive at all and if you're going to believe someone else's load data in those upper echelons without confirming the workup yourself, I have a bridge I'd like to sell you.

I hope I don't sound like a preacher, but I have close intimate knowledge of what can happen. These kinds of answers always seem to be a "thread-ender".

[1-M-42]

Not using a chrono is just like a baseball umpire saying, "hey, that SOUNDED like a strike"....you aren't getting the full picture.

[Latigo]

Just got the word, and the Stanger is getting a Chrono! I'm hoping he;ll keep track of his entire process and post it for us. This should be a good barometer of his RE17 success.

[Mustang]

Ok, so I've seen this same post around the C&R forums, and I have a question.

When you're near the top end on any published data and you've heard that the best performance point is an unknown above the published data, why are you not using a chronometer for the sake of your face, eyes and hands?

They're not that expensive at all and if you're going to believe someone else's load data in those upper echelons without confirming the workup yourself, I have a bridge I'd like to sell you.

I hope I don't sound like a preacher, but I have close intimate knowledge of what can happen. These kinds of answers always seem to be a "thread-ender".

I usually use the "accuracy" load in the Sierra manual as a target, backing off slightly from that and working up slowly, looking for pressure signs.

This is the first time I've ventured into the "ugknown", and I started out with what I believed was a safe start point and worked up in .5 grain increments. The problem is that I'm not sure how "flat" a flattened primer" should look. Even at 49.2 grains of Reloader 17 I didn't get any sticky bolt, separated cases or the like.

I do have a chrono now and will chrono the load (and other loads that I use) to find out what the actual MV is.