Comparing loading data for the Swedish Mauser

[Dougan]

Last year I started loading for a 6.5 x 55 Swedish Mauser - As I intended to use VihtaVuori powder, it seemed logical to use their loading data... Unfortunately I had problems with the loads, varying from sooting to signs of pressure (note: the 'signs' may also have indicated 'poor fit' or generous chamber, and not necessarily pressure).

Having spoken to BLU about it, he very kindly sent me all the loading data he had for the Mauser; which I've now compared...

I already had the Vhit and Lyman manuals, and Blu sent me data for Speer, Barnes, Sierra, Nosler and Hornady - The first obvious comparison is that most represent a specific bullet manufacturer, where as the Vhit represents a powder, and the Lyman is the only independent one.

All the manuals, apart from the VihtaVuori one, give an introduction to the round; and warn about the differences in loading for a modern Mauser and a milsurp - The Hornady manual is the only one to mention the 29" barrel on the M96, and actually used one for the testing...the others just quote a test barrel lenth; which is away several inches shorter.

The data I was specifically looking for was for Viht N160 and a 140 gn HPBT bullet...


The VihtaVuori manual gives: COL of 3.110 for the exact bullet I am using - Starting load of 43.4 - Max load of 46.7

The Speer and Barns manuals couldn't be used for comparison as they neither quote Viht powder or a comparable bullet for this load.

The Sierra manual give a COL of 3.050 for the exact bullet I am using...but doesn't quote Viht powder.

The Nosler and Hornady manuals both give more or less the same data - The 140 gn bullets quoted are not exactly the same as an SMK, but are clearly fully seated at a COL of 3.025 - And starting loads of 37.0 - Max of 41.0

The Lyman manual gives a COL of 3.050 for a HPBT - Starting load of 39.5 - Max load 44.0


So in comparison: The VihtaVuori manual gives a COL that leaves very little of the bullet in the case neck, where as all the other manuals suggest seating either more than half way down the neck, or fully seated - And the Viht starting load is between 4 and 6 gn higher than all the other manuals.

My problems developing a load for this round were partly down to my lack of experience (some may say stupidity) in not fully understanding the differences in pressure caused by what seem to be small changes in seating depth - However I do think that for this specific caliber the Viht manual may not be the best for a relative beginner loading for an old milsurp...

[Alpha1]

So what load did you finally settle on and what cartridge over all length did you use.

[Dougan]

Well that's the thing Alpha, I haven't settled on a load yet - I only switched to N160 this year and have had only one test so far...I tried 43.0, 43.5 and 44.0 with an 140 gn SMK seated to 3.080 (as I didn't trust the robustness of 3.110) a few weeks back, but got heavy/sticky lifts on the bolt with the 44s so stopped...

...I had loaded some more to try at 41.0 and 42.0 for this Sunday - But since getting all this info, I'm going to pull them and re-load them at the COL recommended for the specific bullet type by Sierra and Lyman (3.050), with the powder between 39.0 and 40.0 gn to start...

...I'm not expecting sooting as the cases are once fired neck sized, so fit nicely...but am hoping for a mild recoil (less than factory), and after the cases are cleaned again, that they still fit nicely without a slight squeeze/crush...

[Alpha1]

I use 43.2grains of N160 in mine. Cartridge overall length 3.1390 any thing above 43.8grains in mine and I get heavy recoil and the bolt can get sticky. 44grains is deffo to hot for mine.

[Dougan]

What type of bullet?

[Alpha1]

139grain Lapau scenars bullet.

[Dougan]

If your using Scenars then your're stuck with the Viht data, as there doesn't seem to be any other for a comparable bullet - your loads do seem to fit with the data though, all be it with a slightly deeper seating (Viht manual gives 3.150)...do you not find them a bit long for loading from the magazine?

Interesting what you've said about it only taking a little extra powder to go from your chosen load to one that's too strong...when you look at the various manuals there appears to be less movement between min and max loads than there is for other popular loads (.303, 308 etc.).

[ovenpaa]

There are many other suitable powders for the 6,5x55 other than Viht. H4831 can give a gentle load and Reloder 19 works.

[Dougan]

There are many other suitable powders for the 6,5x55 other than Viht. H4831 can give a gentle load and Reloder 19 works.

Absolutely, as Blu and others have said - but I still have a half tub of N150, and now have a full tub of N160 as many recommended it for the Swede...so will continue to use it for now.

I don't think the type of powder (though the slower 160 is more suitable for the barrel length than the 150) is the problem...more that I've been using too much for the seating depths...

[Alpha1]

If your using Scenars then your're stuck with the Viht data, as there doesn't seem to be any other for a comparable bullet - your loads do seem to fit with the data though, all be it with a slightly deeper seating (Viht manual gives 3.150)...do you not find them a bit long for loading from the magazine?

They were fine from my magazine.