This replacement barrel from RB Model is designed for the recent Pit Road/Trumpeter kit of the Soviet B4 Model 1931 203mm Howitzer (kit #G11/02307).
One thing that has emerged since doing the kit review was the barrel appears to be short in length and this replacement barrel addresses that as well as the fit issues with the kit barrel. But as with the kit review I don't have any firm data at this stage to substantiate this and will have to take this and dimensions of the metal barrel at face value until appropriate data is available.
As with all RB Model sets there are no instructions or fancy packaging, just the parts in a zip lock plastic bag and a simple B&W label which is not really a problem with this barrel as assembly is very straightforward.
The set has the aluminium barrel tube the brass flange already fitted in place on the barrel tube so there is no cleanup other than a few metal burs inside the muzzle from the rifling machining. This is easily removed with the point of a fine file with the muzzle drilled out to a depth of 15mm which gives a good appearance with the larger calibre.
Brass and aluminium barrel
About the only "gripe" would be that due to the size of the bore it is a little noticeable that rifling is parallel and not curved around the tube as it should be in real life,and as it does with the etched rifling in the kit.
Rifling in metal barrel compared to etched kit rifling and poor fit of kit barrel tube halves
A quick comparison with the kit plastic barrel shows the increase in length with the reast of the barrel matching in diameter and contours. This makes for easy fitting to the kit as you simply replace the kit barrel with the metal one with no alterations required to the kit or metal barrel, all very straightfirward.
One thing to watch is the spaces between the brass fitting on the barrel as the narrow spacing should be positioned at the top and bottom of the barrel with the wider spacings at the sides. I positioned these incorrectly in the images below but didn't notice till after the pics were taken, so watch this as it's easy to get wrong if not careful.
Close up of barrel detail
Overall view of the assembled barrel fitted to the kit.
Note; I didn't notice till after the pics were done that the barrel is positioned incorrectly,
the narrow spacing on the brass fitting should be at the top and bottom of the barrel,
not at the sides as shown in the image. Apologies for that.
This is another excellent yet simple barrel set from RB Model with no clean-up required, very good fit and no alterations required to fit to the Trumpeter kit gun, nothing could be easier.
This set will add considerable improvement to the kit barrel with nice collar and barrel detail to overcome the poor fit of the kit barrel.
The rifling is the only minor issue with the length to be confirmed.
Highly recommended
Thanks to Leo at LionMarc Model Designs who now carry the full range of RB Models barrels for the review set.