6mm Crusader

[Elwood]

Having shot in local 300/500/600 yard F class for the last two years using my 6BR I thought it was a time to change. Although the 6BR was a superb round to shoot and on a calm day hard to beat when the wind picks up the 6.5's tend to rule the shorter ranges, mainly 6.5-284 and now 6.5x47.

 

Now I loved the low recoil and economy of the 6BR and my immediate thought was to try either a 6 Dasher or 6 XC, the Dasher just doesn't have enough in the boiler room to shoot the 115 Dtac (my chosen bullet) and although the 6XC does I believe its right at the end of its limitations. This leads me onto the 243 or 243 AI but I then did a bit more research and found the 6 SX (Super X) now known as the 6 SLR (Super long range) it's based on the 243 and is formed by running it through a forming die where it basically becomes a 6 XC but with a bit more case capacity and a longer neck than the 243. After doing some extensive research on the net about the 6SLR I logically decided on the 6MM Crusader.

 

Anyone watch Tool time with Tim Allen if you did you will be familiar with the line More Power, this is what the 6 Crusader gives you, a lot more power. The ballistics compare with the 6mm AI or 244 Mashburn and not far behind the 6x284. Anyone of these cartridges will get you up to 3300 fps using the 115 Dtacs. Now I will conceded that I have strayed completely off line in my search for a economical and light recoiling case for short range F class, what I now have is a cartridge that can compare very closely to any of the 7mm's and beat most 6.5's.

 

Here's a photo of the different cases, from right to left 6BR, 6.5x47, 243, 6mm Rem, 6mm Crusader and 6.5x284

 

 

A brief history of the 6mm Crusader, it was designed by George Gardner of GA Precision and was designed to shoot high power. The case needs to feed from a magazine and extract from the chamber without fail, this is where the Crusader has the advantage over the 6mmAI. The Crusader has a slightly tapered wall for easy extraction and uses a 32 degree shoulder which allows it to feed from a magazine.

Case forming, this is pretty easy really, just load up some 6mm Rem cases and fire them and you have your 6mm Crusader, however there is a much harder way of doing things which naturally appealed to me! The 6mm Remington is a necked down 257 Roberts which is based on the 7x57, so all you have to do is buy some RWS 7x57 brass and have the patience of a saint or enough money to invest in a lathe!

RWS brass is superb if a bit costly, to start the forming process you run the 7x57 case through a 243 FL die with the expander ball removed this necks down 80% of the neck and to finish of the last 20% you need to run it through a 6mm Rem FL die with the expander removed, see photo below. I didn't like the idea of going from 7mm straight down to 6mm so I tried to buy a 257 Roberts FL die, alas I couldn't source one but I did manage to get a Hornady universal 6.5 neck die, not one of my better ideas as there wasn't enough support for the case wall and I have now turned one 7x57 case into a rather nice if not small candle holder (available to the highest bidder)

 

From right to left, the parent case 7x57 Mauser, after running it through a 243 FL die, after being run through a 6mm Rem FL die and the finished loaded case.

 

When things go wrong, this will be on Ebay tomorrow so get those bids in quick.

 

The reason I went with RWS was because it needs to be neck turned and I can now make my chamber a tight neck, what I didn't realise was just quite how much neck turning would be involved. Once the case has been expanded back up to 6mm, remember that the case has been formed with the expander removed so it measures about. 2645 so after expanding the neck back up I now have a case that measures .280 I need to get this down to .270-.271 with a loaded round, the chamber measures .273, that equates to four runs through my KM neck turner and several arguments with her indoors, and to be honest they could be turned down another 1 thou (no not her the cases!)

 

So we now have our cases all ready to be fire formed, the easy way but more expensive way is load up a stout load and shoot them, there is of course a much more fiddly way to do things which was my chosen path. Bullets and powder are not cheap these days neither are barrels, so I chose the cream of wheat method to fire form, this will be a basic explanation of how it's done, Spud has done a very good video on YouTube.

Firstly you need a fast pistol powder I chose Unique as that's what I could source, Bulls eye is a better bet, the faster the powder the less powder required. Fill the case up completely with powder and then weigh the charge, use 10% of the weight as a starting load (Example 55 grains = 5.5 grains) maths lesson over. This is your starting load, increase your load in .5 grain increments, the load that gave me a formed case was 14 grains with Winchester brass and 15.5 with RWS brass.

Prime the case, I chose pistol primers but I'm told any primer will do, drop the powder in the case and then fill the rest of case with cream of wheat (Semolina, Sainsbury's 2 for 1, bargain) just above neck shoulder junction and then insert some toilet tissue as a plug, I did buy some wax which I think is for used for removing women's body hair, I found that the tissue was far easier to use and I now have the added bonus that I already have one birthday present for my long suffering girl friend, I'm sorry but that moustache really has to go. I would advise that you don't use your powder thrower to measure the Semolina, it's incredibly dusty, and I just used a teaspoon and weighed it in the pan.

 

Cases filled just above the neck junction.

 

And tissue wadding to keep everything held in.

 

On a serious note now, please please pay 110% attention when filling the cases with pistol powder, as a double charge would have disastrous results, as far as I'm aware it's impossible to double charge a rifle case with normal rifle powder, please correct me if I'm wrong, but with pistol powder I can get three charges in the case and even then it wouldn't over flow.

 

So we now have our cases formed, hoorah.

The powder of choice would be Viht N560 and RL25, I use RL25 in my 7WSM and although it works great I don't like the powder as it is so inconsistent from lot to lot, the other choice would be H1000. I started of testing for seating depth at 100 yards, no surprise that the 115 Dtac wanted to be into the lands to shoot, I ended at 10 thou in but I might fine tune it later. I then went back to 200 yards and tested for groups. Everything looked good with half inch groups being the norm until I went over 3150 fps then they started to open up, I settled on a quarter inch three shot group at 49 gains of N560. The next day I loaded up ten rounds with the accurate load and went back to 300 yards to test, I was looking for half MOA or less, I dialled in the elevation from 200 to 300 and was somewhat surprised that I was shooting high (I later realised that my barrel had just increased by 70 fps), anyhow the groups weren't acceptable so back to the reloading room I went feeling somewhat deflated.

The next day I tested neck tension, running 4/3/2 and 1 thou, 4 thou worked nicely giving me a five shot group of just over 1 inch at 300 yards, as the neck tension decreased the groups opened up, I then tried sizing just half the neck but found no noticeable difference. The load I settled for gave me a nice 3130 fps with a ES of 16, however I'm going to try some lighter loads as it appears the Dtacs don't like to run over 3150 fps and as my loads were worked up in cold weather the warmer summer may well increase my fps above the accuracy node.

 

I'm shooting my first F class match a week today so it will be interesting to see how things work out.

Would I do it again? No I *^"*!*" wouldn't I'd go for the 6 SLR, only joking, time will tell.

 

Sorry there aren't any photos of the rifle at the moment as the stock is being painted, when I get it back I will post some photographs.

[brown dog]

Excellent read Ian; you must have the patience of a saint to do all that - I can barely summon the will to reload 308

 

Your 'ratchet' up the power curve is exactly what my brain does whenever I think about this sort of stuff - be very interested to hear how it turns out; the 115DTAC out of a 243 is already impressive; this thing must be better yet.

 

Dare I ask, what's the story on likely barrel life?

 

(-and you've finally solved for me what 'cream of wheat' is )

 

 

[can't remember, is your 6br in an AW?]

[Elwood]

BD, suggested barrel life was 1200 rounds for F class but I have been in contact with someone in the US who has 1500 rounds and still shooting half MOA. Most 6mmAI owners say that accuracy will drop off at 1000-1200 rounds but sometimes a 1500 round count can be achieved, hopefully the shorter distance will be a little bit more forgiving, plus the slower burning powder that isn't being run at full throttle and that nice long neck which I'm led to believe takes up a bit of the torching effect.

49 grains of N560 is nearly 3 grains below the maximum load, I took it up too 50.8 which gave me 3202 fps but I suspect that will now be about 3270 fps, so the 3300 fps will be easily achievable but illegal at Bisley! but if the accuracy isn't there it doesn't matter.

 

I will be brutally honest, if the accuracy node for the 115 Dtacs is below 3150 which it appears to be then the 6x47, 243, 243 AI, 6 SLR and possibly the 6XC are all probably a better bet

 

The original cartridge was designed to fit into a AI magazine with a COL of 2.950 and that was seating the bullets 10 thou into the lands. On the few dummy rounds I made this would seat the bullet a fair way into the case so I had the free bore increased by 100 thou. But the answer to your question is no my 6BR wasn't a AI, my 22BR and 7WSM both use the AISC system though.

[foxing2night]

Nice one Ian,,

 

Good read and well writen,,,,

 

I think that i will stick with the 6.5x47????

 

thats is costly enough

 

I must admit that i still fancy a 6br????

 

All the best, Darrel

[The Gun Pimp]

I love hot 'sixes' - I've had two 6-284s plus my own shortened version I call the 6mm Xtreme.

 

My first one - built by Callum Ferguson - shot like the proverbial laser in 1000 yard benchrest - til one day, after 750 rounds I started to lose the odd bullet - on the way to the target. Callum said that the barrel was burnt for the first 18 inches and just ripping the jackets!

 

Now, I don't expect more than 450 to 500 rounds - of the kind of accuracy they will deliver.

 

Won the UKBRA 1000 yd BR Championship with my last one using 115 DTACs at 3250fps - after 450 rounds it wouldn't group less than one MOA at 1000 yds.

 

I reckoned I could get the same performance with a 243AI and DTACs. Less powder - more barrel-life! I got em up to 3200fps OK, with good accuracy - set a new UK 600 yd BR record - but the barrel didn't last any longer and it just wasn't as good as 6-284 at 1000 yards.

 

I'll build another though!

 

Cheers

Vince

[brown dog]

I must admit that i still fancy a 6br????

 

All the best, Darrel

 

Darrel,

 

Dave (6mmBR) kindly sent me a couple of dummy 6br rounds....placed about 1cm forward in the mag they cycle perfectly in the AW .....and eject

[6mmBR]

Cracking write up Ian. Looking forward to seeing the rifle in action next weekend.

At that rate of proposed barrel ware shall I order 2 tubes

Cheers

Dave

[Elwood]

Cracking write up Ian. Looking forward to seeing the rifle in action next weekend.

At that rate of proposed barrel ware shall I order 2 tubes

Cheers

Dave

 

Haha, but Vinces cases didn't have the sexy long neck to soak up some of the burn, yes that's all the hope I'm clinging onto now

[baldie]

A very interesting and imformative article Ian, Thanks, really enjoyed it.

It sure is a pretty case that, and what a neck. Its just got to help with reducing throat erosion.

[The Gun Pimp]

Haha, but Vinces cases didn't have the sexy long neck to soak up some of the burn, yes that's all the hope I'm clinging onto now

 

 

Well, that was part of the thinking behind my 6mm Xtreme. I lengthened the 6-284 neck by 50 thou. reducing case-capacity at the same time (you can't use it all) but it made no discernable difference!

 

To be honest - benchrest is hard on barrels - getting five rounds off in 15 seconds must really get that barrel red hot. With something like F Class - one shot every minute - I reckon you will increase barrel life by 50%.

 

A 7mmWSM will do about 700 rounds in F Class whereas it's more like 450 in benchrest.

 

Cheers

Vince

[Elwood]

Well the Crusader had its first serious F class outing on Sunday and performed very well indeed.

 

I managed a fourth place with the Dorset Riflemen, shooting a 75.10 at 300 yards and 75.6 at 600 yards with half MOA V bulls ( don't snigger about 300 yard F class, dropping a V bull at 300 is like dropping into the four ring at 1000 yards!

I was really pleased with the vertical it held and it appeared to ride the wind quite well, although it only shot 1/2 MOA less than Dave's 6mm Hot and the 105 Berger VLD.

 

I will be testing it at 1000 yards in March.

 

A bit of confusion over the size of the V bulls, we now think they may have been 3/4 MOA!

[andybrock]

Very interesting read Ian sounds a good round, one tip though never, ever give a woman hair removal products as a present that is if you want your town halls to remain where they should be

[6mmBR]

It was a good comp and very tight at the top.

The Crusader beating the 6x47 by one V bull

It will be intersting to try the Crusader and 6x47 side by side at 1000 yards.

I've still got to test that Rel 17 load pushing the 105 @ 3240fps

Cheers

Dave